"In October I bought a brand new 2012 Mustang convertible with the stick
shift. (It had 200 or so miles on it--it had got caught up in the
Takata airbag mess, so the dealer couldn't sell it for ages.) Got a
nice discount too--it wound up being the price of my daughter's Kia
econobox. "

Well first of all you just disconnect those air bags and watch where you are going. I bet you still can in a 2012, but you may have to put a resistor in there or something to simulate a load.

One thing that probably helped your negotiations on that car was that people today don't really go for stick shifts. They have to play farmville, text and talk on the phone whilst keeping an eye on their chipped dog and watching insidd their house to see if anyone is stealing their plasma TV. Also they have to update their facebook every three minutes or their dear friends (who would kill them in an alley usually) don't think they're dead. Or something.