re: not -- got to be sure we give you advice in the right direction!

If you're really just looking to save wear and tear and save money, I'd reserve a compact or economy. The other way to play it is to surf the frequent flier and rental care forums here for coupon codes -- maybe there's one for a hybrid. Alternately, hertz has crazy good codes with southwest (even if you dont fly them). When you get to the counter, talk your way into the prius for cheap, or free if they're out of your car. I think you'll save money that way. You'll pay more guaranteeing it in advance -- only helps if you're trying to drive before you buy or something.

I'll be away on vacation; be sure to post what actually happens, your mileage, and such!