Nascar 2000 is pure crap. (there, I said it, someone had too)
If you want a Nascar game for the pc, the 2 best choices are Nascar Heat & Nascar4.
As others stated Nascar4 is very simlike & you will need to put in some hrs of "tracktime" to run up front with the computer AI at 100% difficulty.
Nascar4 has a huge online racing community of all skill levels & no matter what time of day it is, its usuall easy to find online opponents.
Nascar4s graphics are excellent if your pc has the power to run in higher resolutions.
And as stated earlier, there are many many carsets & custom painjobs available online & you can paint your own car.
Nascar Heat is a bit more arcadish & allows you to adjust the difficulty of how your cars handle & the AI difficulty as your skills improve.
Which is nice for beginners & people who dont wanna spend hrs logging lap after lap & making small adjustments to shave1/10th of a second off their lap times.
You can just race in "normal" mode which = "arcade" where the car is easy to handle & hard to spinout until your skills improve enough you can "up" the difficulty.
Nascar Heats difficulty goes all the way up to "hardcore" mode where the ai & physics are about on par with Nascar4s.
As far as Heat online, I dont know, I play Nascar4 when I wanna raace online.
Heats graphics are great too, it looks slightly different from Nascar4 but its a great looking racer.
Both games feature great graphics ,car damage & spectacular crashes.
Stay away from any Nascar games made by EA for the pc, just do a search for reviews, youll see what I mean.
EA only has one decent Nascar racer & called Nascar Thunder & is only currently available on the XBOX & PS2, no word on a pc version yet.
Nascar Thunder is an "arcade" nascar racer. BTW
I loveNascar Heat & Nascar4 theyre both great games.
Id suggest Nascar Heat to newbies to racing who want as close to the real Nascar experience as they can get without spending lots of time learning to drive the car.
And I suggest Nascar4 to people who like "sim racers" & love spending hrs tweaking their setups & enjoy Paying for every little mistake they make on the track. (thats the way it SHOULD be IMO)
Unless of course youre like me & LOVE Nascar , then just by both.
Go fast, Turn LEFT!