Don't cover it !!!!!!!!!!!!!!!!!

[Grizzly]

I'm sure you have figured it out by now but the older paint's used tend to be porous when it drys out as well as not having the best Adhesion, (modern 2k etc won't be effected but that has its own demons when covered) a cover tends to hold the moisture against the paint surface so after a couple of Hot and cold Cycles you'll get bubbles.

If you must put your car out side a coat of Wax then a coat of Hard sealer will help protect it better than a cover but if it was me i'd be renting a Storage unit/Box Container/Garage for the winter.