Thanks ChrisA!
Actually, i was worng about the distance. It is 250 "feet" instead of meters.
Someone recommended me the AFS VR Zoom 70-300 f4.5 ED , but how i said, i dont know much about lenses. I just dont want to use a p&s camera.
That's still pretty far away. I think your price range is unrealistic if you're expecting great shots. When I got to shoot trackside at Indy unexpectedly, I wished I'd had at least a 300/2.8. The 70-300 is above your price range and f/5.6 at the long end- unless you can shoot at very high ISO, or you're shooting mid-day I think you're going to be disappointed. The 70-300 rents for ~$35/week- I'd suggest renting one before forking out the money.
A lot also depends on where you are on the track. The best car shots are going to be in the corners, and after four shots of for cars in one corner, you're going to be bored if you can't move to another corner. You can probably pretty-much forget trying to catch a shot on the straight-away from the stands- side-on is difficult if the cars are moving fast.
You'll also want enough room to pan with the cars, so you can get the wheels in motion- generally for that I think you're going to have to be in the 1/250th of a second or so range.
Image stabilization is useful, since you're panning, but not essential. I've shot motorcycles from trackside (with a press pass) and used an unstabilized 400mm f/2.8 lens on a tripod (yes, motorsports heresy- but with a pass, you're shooting from inside the corners- which is way safer no matter what as crashes and out-of-control vehicles go outside.) Even there, I'd wished I'd spent a couple of weekends panning near the freeway or at a go-kart track first (but with bikes, as long as you get them leaning heavily in the corners, they're happy!.) Don't forget to keep the vehicle off-center so it has room to "move" into.
If you can't get trackside, then I think you're probably going to want one of the Sigma n-500mm lenses if you can get a high-enough ISO for f/6.3 at the long end.
Here's where I'm going to disagree with ChrisA:
IS/VR/OS is useful when panning quickly to catch a speeding vehicle. Especially if you're on a monopod or hand-held and you're panning with a low-ish shutter speed.
1/500th to 1/1000th is likely to be too quick for all but the fastest portions of the track(where getting the shot is proportionally more difficult,) in the corners (unless it's roundy-roundy taxicab racing) you'll get frozen wheels which make the images look dumb and static. I don't shoot a lot of motorsports, so I like to be in the 1/125-1/250th range in the corners. People who shoot it a lot are probably in the 1/30-1/60th range in the corners- side-on in a straight, you can probably get away with 1/500th, but in a corner the vehicle is going to look like it's parked there, and that's going to *suck* for a racing picture.
Paul