Obviously, there is NASCAR, Indy, etc.  Autox, rally, etc.

Trying to figure out what each involves--track type (Oval, etc. for Indy/NASCAR is pretty obvious--, but are there distance/track size limitations or requirements)?

What kind of a setup is Autocross?  Rally?

Now as to classes of cars--

What is a GT2 vs GT3?  Horsepower/Weight requirements?  Street legal or not?

What (aside from aerodynamics) makes an Indy car faster than a Stock (NASCAR) car?

And, finally-- common (or reasonably so) street cars--what kind of class do they race in?  Say a stock 911, BMW M3 (or, better yet--I like the E30 M3), etc.?

In your opinion, what are the best cars in each class (or for each type of racing)?  Does one design have a distinct advantage in any given type of racing?

I like LeMans/Rolex sports car series and SCCA. SCCA is the kind with almost stock cars.

I'll let the more knowledgeable answer the rest.

BTT>

Most Stage Rally is run as "time trials" on closed portions of roads (gravel, tarmac, snow, etc.)
with each car running the stage at 1min. intervals. Not much wheel to wheel...

One of the fewer motorsports where there a 2 people required in the car to race.
Co-Driver(that's me) basically has notes describing the roads (turns, severity, distance, etc.)
Driver puts his foot in it and tries to keep it out of the bushes!


Current fave: Open Class 2.0T WRX...she's gettin' painted this week!