I purchased my RX8 used almost 2 years ago. My engine started "fluttering" 4 days after I bought the car. I have only had problems since. If your RX-8 is not idling correctly, you need to have the engine replaced. Finally after 2 years of problems, mine are about to be solved. If you are looking to buy this car, please know that it is not a grocery getter. You have to heat the engine completely up before you can turn it off. Do yourself a HUGE favor and do some research. You would be amazed at what needs to be done for the upkeep of this car. I love mine to the point that I cant trade it in. Make sure you are willing to put in the time and effort to keep it up.
Sporty looks, handling, everything about it.
Engine flooding problems (computer issue) and "fluttering" engine issues (if yours is vibrating hard while stopped, you need to get it into mazda and have them do their 30 min. road test asap. you may need a new motor.)