I would choose Southern California. It has VERY low humidity and NO snow unless you're in the mountains..... Especially if you can find a car in the desert! Look into Palm Springs, CA lots of older folks who stored these cars until they passed and wives or vise versa don't know what to do with them. You'll find yourself with a low mile, pristine condition car for a VERY low amount.

The only thing that is hard to these cars down here are the drivers and the heat, if you're looking into the desert that is.... The heat is very strong, so I imagine cars here will have a higher chance of having cracked dashes and faded interior.

__________________
2007 BMW 328XI