can i ask about the SN car seat you have. i stumbled across one on the britax seat, and altho dd2 doesnt 'need' one, i think she would be safer in one. she is onyl 2, but the size and weight of a 4+yr old. when she falls asleep in a high back booster she slumps and looks uncomfortable plus she slides down under the belt a bit. cant really use the harness seats anymore as she exceeds the weight limits on normal 2nd stage seats.