Hmm...they're cool cars, but you need to make sure you're aware of the "quirks" of the rotary engine. First off, as mentioned above, rotary engines are designed to burn oil; if I remember correctly, the carbon residue it creates helps lubricate the seals for the rotor (or something along those lines). Also, they need to warm up for a few minutes before you drive them, or you WILL foul the spark plugs. (Funny story about this further down). The problem with fouled plugs is so common that they even give you an extra set of plugs if you buy a new RX-8, apparently. I've also heard gas mileage is not very good. All these things are unfortunate, because as I said, they're really cool cars in my opinion. I'm going to have to suggest staying away from them...but then again, I have no personal experience with them.
Also, the post below reminded me of a voluntary recall Mazda performed on the '04 and '05 models (we're probably thinking of the same thing). Basically, if the car doesn't pass a vacuum test, the engine gets replaced. Here's a link:
Mazda Plans Recall of Troubled RX-8
Funny story: My dad manages a collision repair shop. A middle-aged lady brings in her RX-8 for repairs, and she mentions how it needs to warm up before driving. Of course, my dad thinks, "Whatever...sounds like dealer-based hype, or some equally stupid statement out of the owner's manual." So he ignores that, starts up the car to move it, waits like 20-30 seconds, pulls it inside, shuts it off. Tries to start it up the next morning, and bam...fouled plugs. He put his foot in his mouth on that one...I found it pretty amusing.