Here is some information from Britax on the voluntary recall of the Frontier:
Britax Frontier™ Harness-2-Booster [Recall]
Model Numbers: E9L54E7, E9L54H6, E9L54H7, and E9L54M6 (black harnesses)
Manufacture Dates: April 1, 2008 through September 14, 2008
Model Number: E9L5490 (beige harnesses)
Manufacture Dates: April 1, 2008 through September 17, 2008
Total of 31,492 seats included in the U.S.
To determine inclusion in recall – verify manufacture date:
Description of the Defect
If the harness straps are loosened one strap at a time with excessive force, then the harness straps may become loose or detached from the metal yoke located on the back of the child seat. If the harness strap becomes loose or detached then the condition can be corrected by inspecting the back of the child seat and reattaching the harness straps. If the harness straps are properly attached to the metal yoke then the child seat can continue to be safely used. Ensure that the harness has a comfortable but snug fit around the child.
What You Should Do
Britax is providing with this Notice a Recall Kit that contains two rubber caps which are to be placed over the ends of the slots in the metal yoke. The rubber caps will prevent the harness from detaching from the metal yoke and can be removed in the event that the seat is used in Booster mode or in order to remove the cover. An Instruction Sheet in the Recall Kit will provide specific instructions and photos to aid in installing the rubber caps. This modification involves removing an installed child seat, inspecting the harness/yoke attachment and installing the rubber caps which should take no more than ten minutes. These kits will begin mailing out the week of January 5, 2009.
Direction to consumers with product included:
If you have registered your child seat with Britax before the launch of this recall, by returning the registration card attached to the product or via our website, no action is needed. A Remedy Kit will automatically be sent to you via US Mail starting on January 7, 2009. You should receive it within 7-10 business days from January 7, 2009.
The problem can be resolved by simply attaching the rubber caps to the metal yoke on the back of your seat. Britax will mail you the rubber caps and detailed instructions for installing it. You can also find instructions on our website www.BritaxUSA.com or www.FrontierRecall.com.
Seats manufactured AFTER the September dates above have a row of stitching at the very end of the loop to stiffen it up. Therefore, seats manufactured after the September dates that include the implementation of that enhancement are not affected.