Lens question

Hi everyone, just got my D3100 with the standard lens kit.

I'm looking to go to a race track soon and want to get some shots of cars going round. How good is my current lens for that sort of task?

I'm not sure how close I'm going to be able to get to the action but I want to be able to get some cracking shots..

Nikon AF 70-300mm f/4-5.6 G Lens

is this lens any good can anyone tell me.. I know its cheap and I know I'd have to manual focus but overall quality is it good for zoomed shots.

cheers and sorry for the long winded questions!

Okay, it`s cheap. Okay, it has a fairly long zoom. But it is incredibly, unbelievably slow. It doesn't find focus for many long seconds. You said racetrack , you didn't specify horse or car. If it's horses it may be marginally acceptable, if it's car racing forget it. Keeps rotating back and forth. Very annoying. Picture quality is way below what you would expect from a Nikon lens. Not one of Nikons better efforts.
The above is My $.02 cents worth! but probably only worth a penny!

Having a D40 and I used to have the same lens you are talking about I think it would be hard for you to do. For one thing motion blur zoomed out. Another is the tiny focus area zoomed out. Good luck getting it just right with the detector light. I think you should buy a 55-300 vr or 55-200 vr. Boost up the ISO as well.
I hated that lens so much I took the front element out and made a macro filter out of it and tossed the left overs.