Jumping into this thread because I have a similar question. DH was just in an accident where he T-boned another car that pulled out from a shopping center across two lanes of traffic. The car was drivable, neither of the back doors were affected, and the airbags did not deploy, the two seats were not occupied, and he was not injured so according to Britax's 5 criteria we would not have to replace the seat. However, based on the fact that DH was going 45 mph before he hit is brakes, the insurance company deemed it a moderate (not minor) collision and recommended we replace our seats. So we did. But would you feel comfortable donating the old seats or keeping them as backup?
Mom to a spirited, red-headed, former 28-weeker 10/2009 and a more mellow monkey 12/2013.