Originally Posted by J Ritt

In addition to the other reasons mentioned...something very important to consider when racing your 350Z...$30,000 purchase price, +$22-28K for prep...that's close to $60K. Then you need to plan on at a bare minimum $1000 per race weekend for rubber, brakes, fuel, entrance fees, etc. To top it off, you have to be prepared to write your $60,000 car off if you total it while racing. That's a lot of bank for the average joe to swallow. That's why spec miata and rx-7's are a lot more attractive for club-level road racing.
As for Grand-Am, etc., that's some serious racing, and waaaaay out of most people's league. Just to get a drive in one of those cars for a race weekend you'll have to pay $20,000 to the team owner. Also, those cars are much, much, much more expensive than $60,000...try triple that!