We generally re use components. Stuff like frames we use for multiple years if it was good. So yeah, we tear old cars apart most of the time.
We kept the 2010 car together-ish to bring to open house and stuff like that. Stuck a bike motor in it this year.
Things like spindles, uprights, brake parts, and rear ends we only have enough to keep one car running at a time. We do have multiple sets of shocks, although we are trying to sell off some of those (on that note, anyone want some Fox Floats for a Honda 400ex?). Stuff like control arms/trailing arms are pretty much car-specific.