Because Darren has already done a much more formal review, my review will be, well, less formal, lol.
I managed to scrounge my way into borrowing a Britax Frontier (now replaced by the Britax Frontier 85, please see our new review here) from my local Safe Kids coalition. Aw, it was actually easier than that: they like me for some reason J and let me borrow seats from time to time, but the seats are usually old or taken from a checkup event. The Frontier was, mmmmm, fresh out of its bag and had that new car seat smell. I’ll tell you straight off—I’m a hard one to impress when it comes to car seats. I’m a skeptic. I’ve had enough to know what I like in a seat, what I don’t like in a seat, and what will work in my ’05 Sienna. Do I like the Frontier or not? Read on and find out.
Setup: The Frontier comes with the recline block (foot) set up in booster mode rather than harness mode. That’s counterintuitive to me since the vast majority of users of this seat are purchasing it to use in harness mode. Having the block in booster mode allows the seat to sit upright rather than tipping backward when it’s sitting on the ground, so I’m sure that’s one of the reasons that Britax has shipped the Frontier that way.
Harness Mode: Changing the harness height is a snap. Loosen the harness first, then on the back of the seat, lift the lever and adjust the harness to the correct height above your child’s shoulders. It’s really as easy as that. There are 8 different positions. Let’s talk about the harness adjuster on the front of the seat. I have fallen in love! I have heard parents say that the harness adjuster on the Britax Roundabout is the easiest they have ever used. No no. They have never used the harness adjuster on the old style forward-facing only Maxi Cosi Priori (as my friends know, it’s my all-time favorite seat): the MCP, as it was known, had the smoothest, easiest harness adjuster. Until now. I don’t know what Britax did to finesse this harness adjuster, but they did it right! This is also the first time I’ve had a chance to work with the new buckle that clicks on both sides. Hooray! I really like it! The old buckle style that clicked only after the 2nd buckle tong was inserted didn’t bother me . Until now.
Harness Mode Use: My 6 yr old, 44 lbs., 46” dd and I really liked using the seat in harness mode. The first couple of times I pulled the harness too tight (see above for that super smooth harness adjuster) and she simply couldn’t reach the harness adjuster lever to loosen herself to get out of the seat. Oops! Once I loosened up the harness a bit, she was fine (she doesn’t have the strength to pull the harness tight enough so that it passes the pinch test). She also had lots of growing room in harness mode, thanks to a shortish torso and tallish harness slots J.
Booster Mode: Switching to booster use was pretty easy. Removing a harness is always easy, lol. Britax has a spot on the back of the seat where the metal splitter plate (that roundish T-shaped thing to which the end of the harness straps attach) snaps when the seat is in booster mode. You must remove a screw so that the head restraint moves independently from the backrest where the harness slots are; you must procure a Phillips screwdriver. Other than that, it’s easy to set up. Oh, and for those of you who are anxious about your booster seat just sitting there on the vehicle seat, it installs with LATCH when in booster mode!
Booster Mode Use: Using the seat in booster mode wasn’t as easy. It was a combination of the way the s
eat belt came out of the passenger side seat bezel and the size of the Frontier itself (see close-up photo). Dd had trouble pulling the seat belt around the Frontier to the buckle because the car seat sat higher and forward of the buckle. Combine that with the floppy buckle and she needed help when she usually doesn’t with other booster seats. Granted, she was using the Frontier in booster mode long before I would switch her to booster mode and the longer arms that come with age would help. The fit of the seat belt on her was excellent though.
Miscellaneous Fun Stuff: Of course, dd loved the pink cover. She’s into all things pink now, much to my chagrin <grimace>. Purple I can handle, but pink? Gotta keep the kids happy, eh? At least the black on the sides balances it out. There are cup holders on both sides. I tend to think of myself as a fairly handy person. I can install tether anchors, use a drill, have even used a jackhammer, but those cup holders left me scratching my head. I kept trying to pull them down to get them to open and they were just as stubborn as I am. And then <music plays> it hit me. To get them to open, you pull the thumb tab on them up and out and they will sweetly-as-you-please open. Gah!
Annoyances: Really, I think most of my slight unhappiness with the Frontier came when the seat was used in booster mode; it really shines as a harnessed seat. First, when converting it to a booster seat, you must remove a screw from the head restraint and keep it safe. *I* would put the screw in a Ziploc bag with the harness and keep it all in a safe place, because you’ll need that screw if you want to use the seat again with the harness, but is everyone going to be that careful not to lose it? Surely Britax could come up with a cotter pin or something else that could stay with the seat instead of a screw because I imagine there are going to be a lot of lost screws. The seat has some sharp edges that kept grabbing my hands as I was trying to install the seat (see photo). Ouch! 
Perhaps the cover could wrap around those edges. The belt path is also quite high, which causes problems with some installations. I found it troublesome especially with LATCH since the LATCH adjuster wanted to jam into the back of the car seat when I was pulling the LATCH strap tight. It took some fiddling to get the adjuster situated so that it was inside the belt path and could be pulled tighter. A final niggly annoyance was the cup holders: they just didn’t stay closed. Rather, they preferred a barely open position where I thought they might get broken if knocked into just right.
Overall Impressions: It’s been a long time since I’ve felt excited about a harnessed seat. My kids are just too old now for me to pay much attention to them anymore, so my fancies have turned to boosters. The 
Frontier, however, has made me question just how long we should keep the old faithful Husky around. It’s so plain, sitting there in that soft blue. Dd felt like a big kid sitting the pink seat with the cool pivoting arm rests. I wonder if I can sneak one past dh, who already thinks we have too many seats in and around the house . . .
No, you can’t put anything behind it either. It sounds like a compatibility issue with the Magnum. You might be better off with a dedicated booster that has a built-in recline mechanism, like the Cybex Solution X-fix or Sunshine Kids Monterey (if you want a booster that LATCHes).
Thanks for your reply. I do feel that the seat belt fits my child well in booster mode. However, I still don’t like that the seat can rock back and forth (like a rocking chair) 3+ inches due to the different recline angle of the Frontier and my vehicle seat. I know that I cannot put anything beneath a forward facing seat. However, would it be OK to put a rolled towel or something beteween the back of the Frontier and the vehichle seat back?
I am trying to install the Frontier in booster mode in my Dodge Magnum RT, and can’t get it to sit flush with the car’s rear seat. It seems the Magnum’s fixed rear seat is too reclined. I have the Frontier’s recline block back in “booster mode”. However, when the bottom of the Frontier is flush with the car’s seat, the Frontier back is 2-3 inches away from the seat back. Alternatively, if I pull the top tether tight and get the Frontier seat back to lay flush on the car’s rear seat back, the front of the Frontier’s seat (where the back of the child’s knees rest) is 2-3 inches off the seat bottom. I called Britax and they said to loosen the top tether so that the seat bottom lays flush & that it doesn’t matter that the seat back is not flush. For some reason I don’t trust this, as the booster seat then has a lot of front to back movement. Can you please comment on this. All photos I can find of the Frontier installed in booster mode show the seat and back flush with the vehicle seat and back. (Also, I have no option to move the seat to another position due to other car seats.
I would stick with what Britax advised you, unless it conflicts with the manual. Of course, if you deem that the fit to the vehicle is causing a poor fit of the booster to your child, then that is certainly a concern. Otherwise, boosters will always have some degree of movement since they do not have to be attached to the vehicle to serve their purpose. Using LATCH for a booster is more a convenience feature when allowed. It helps keep the booster from moving around as much during loading and unloading, but probably has little or no affect on the safety of the booster.
For anyone that’s looking for the britax frontier but is concerned about the fabric the sahara pattern doesn’t have the mesh. I would of rathered get one of the other patterns but after reading many reviews of problems with the fabric pilling I decided to chose the sahara. So far so good and my son loves it.
Ah, Shelley, Darren’s quick on the draw! Aside from his great video that he linked to, you can see Britax’s official installation videos on YouTube. Just search for “Britax Frontier install” and you’ll see the 3 videos that correspond with the 3 methods of installation. I’m also hoping to have two of my Frontier installation videos completed by the beginning of next week and I’ll post them on my web site, http://www.CarSeatSite.com/videos.htm and on YouTube as well.
Shelley- have you tried the long belt path? There are a couple videos here – https://carseatblog.com/?p=2386
I haven’t moved this seat since installing it in my car in January 2009. It took me and the car salesman (who also has a 4 year old) over an hour to install it. It was NUTS how difficult it was. I actually bought a Graco booster seat to use when she goes with other people in their cars. I like that it uses the LATCH system in booster mode, however, the seat is so big, that we can’t get it buckled without a struggle. I own a 2008 Patfinder, so it isn’t a small car.
I do like the Britax safety, but this bulky thing is really getting on my nerves! UG I feel as though I wasted my money, since I had to by the Graco one too.
I have the frontier and love it! I do not; however, love the fabric. It does get crude and becomes dirty quickly. I am in the process of buying a washable cover to put on it. I called Britax today and there is one cover that is not that same mesh material.
Jennifer and Elly, I didn’t measure the top slots, but everyone who’s measured has gotten just slightly over 18″. In booster mode, it should be similar to the Parkway and Monarch which are 21″.
Unfortunately, I don’t have pictures in harness mode. I think it may have something to do with 2nd child syndrome, lol. Poor child rarely gets the same number of pictures taken as her older brother does. But Darren has a picture in the first paragraph of his review: https://carseatblog.com/?p=32 .
BookMama, I don’t really have an opinion of the fabric past the color, lol. I did think the mesh would snag or pill fairly easily–just like any polyester would. Where I live, it gets really hot and plush/velour-type is actually cooler to sit on because it absorbs sweat, so I’d prefer to see that type of fabric myself.
nice review! do you have pics in Harness Mode Use? i whout like to harness my 6yo dd in the Frontier.
Now I understand the problems of installing in a 7 passenger sienna. The belts on my 8 passenger in the middle row, outboard seats come from the frame of the car, not the seat itself (the middle seat does that). They also have that adjuster up and down. ANd the buckle in the seat is flush with the seat. Hmm, I just may need a frontier….did you measure the top slots and the height in booster mode?
What did you think of the fabric? I saw my first Frontier yesterday (thanks to Jeanum 🙂 ) and while the overall seat seemed fine, I was thoroughly unimpressed with the fabric. The mesh was much more open than I expected (more so than, say, on my Nautilus), and it seems like it would get snagged very easily, or that crud could get inside the mesh. The plush fabric seemed kind of cheap. I’d much rather see the whole seat plush like most of the Britax convertibles.