It was suggested to us (can't remember where from) that a second hand car seat might have been dropped or damaged in some un-noticable way and so would not be as strong as it needed to be. So it wasn't so much about expiration dates as it was about knowing what had happened to that particular seat. I was kindof unconvinced by the idea of unnoticable damage* but then its your kids so you shrug and fork out for a new seat.
That said, in the UK there's plenty of second hand car seats changing hands via ebay etc.
* incidentally I've heard the same thing said about bicycle helmets, which use similar materials (plastic, polystyrene)
That said, in the UK there's plenty of second hand car seats changing hands via ebay etc.
* incidentally I've heard the same thing said about bicycle helmets, which use similar materials (plastic, polystyrene)