With the upcoming Redstone Update, I see the possibility of improving existing automated minecart station designs. One way of doing so is to vastly increase the storage capacity (or vastly reduce the required footprint) of the minecart storage area using hoppers, chests, and dispensers (or droppers, whichever is more appropriate).
My problem is, how can I reliably break a (presumably empty) minecart with just the environment such that it can be sucked up by a hopper? As far as I know, anything in the environment that can break a minecart can also destroy items, meaning instead of reusing them, they simply disappear.