Well, the tires are going to deflate all on their own. i've been told by people who actually store and ship cars that keeping them at minimum pressure on 4 jack stands or even taking the wheel off entirely and storing them inside is better for the sidewall, which tend to dry rot and crack. That is their logic not mine. If you don't put the parking brake on, and something runs into it, it will move a lot farther, plus it could potentially cause problems with the transmission. I had a friend to which this happened and the shifter was stuck in park afterwards. 1200 bucks and 3 weeks later it was drivable again.

I've grown up around tuner car culture and body and mechanic shops, you really tend to learn by the other people's mistakes.

- Andy