I just formed a single member LLC to buy a small mini-warehouse complex near my house (bad economy fire sale pricing). Part of the motivation was to gain garage space for myself (that other people will help pay for). I'm about half way through convincing myself to start doing driver quality restos and selling them at common man prices. Since my "articles" say "any and all legal business", I've been thinking of buying a vintage station wagon, painting my business name in a quality logo, parking it in front of the warehouse (like Truly Nolen) and writing that off. My research indicates I could also use it to drive to car shows/swap meets, and write off the mileage as well. I'd suggest keeping detailed mileage records of the business use.
There are some detailed guidelines on the IRS site and the SBA site, as well as others.