H.B.
As far as I know, if they can't be resold (because they're too old) then they also shouldn't be donated - giving needy moms old, unsafe carseats isn't exactly doing them a favor. Unfortunately I don't know of any recycling options, the dump may be the only resting place - I can't imagine anything that could be uglier than an old carseat in a garden!! :-) A real shame to throw something like that out, though.