I returned yesterday from a regional CPS Conference in Lancaster, PA that was well attended and very informative.  I had the pleasure of chatting with Russ from Sunshine Kids while I was there and he showed off the new SUPER LATCH (SL) lower anchor connector that will debut in a few weeks on all new Radian SL models (65, 80 & XT).  SUPER LATCH will allow consumers of these new Radian SL models to use the specialized LATCH attachments up to the full weight capacity of the Radian carseat (up to 65 lbs for Radian65 SL and up to 80 lbs for Radian80 SL & Radian XTSL).  However, this will be allowed if, AND ONLY IF, the vehicle was manufactured after Sept 1, 2005.  This is very important to note because if the vehicle was made prior to this date then you will NOT be able to use the SUPER LATCH system up to the full weight capacity of the Radian SL model.  In these cases it is imperative that you default to the vehicle manufacturers’ listed weight limits for lower anchors which is usually 40 or 48 lbs.  This is due to the fact that there was a regulatory change in vehicle LATCH anchor testing (FMVSS 225) that required the lower anchors in vehicles to pass a tougher “pull test” after this date.
Additionally, Radian80 SL & RadianXT SL models will also be rated to 45 lbs in the rear-facing position which is a first for any US manufacturer. 

UPDATED TO ADD – SUPER LATCH RETRO-FIT KITS FOR EXISTING RADIAN MODELS WILL NOT BE OFFERED CONTRARY TO WHAT WAS ORIGINALLY REPORTED.  

Here is a video of Russ showing the new Sunshine Kids SUPER LATCH lower anchor connector: