Don't spend your precious bitcoin for a bunch of mobile chairs.
No but seriously shopinbit is great!
Discussion
But if you do need a car, best to buy with bitcoin directly and not have to go to exchanges.
Absolutely
Probably better to borrow fiat collateralized by your BTC as long as car sellers are foolish enough to accept inferior money.
It avoids capital gains, should get you a better interest rate, and you won't be replenishing the stack at higher prices later -- just paying down your loan valued in melting ice cubes with inflating money.