2000 saab 9 5 station wagon

the transmission was running fine and smooth, park for a min and when I got back in the car the shifter for the auto transmission will go up and down thru the gears but wont engage, is this the transmission or some type sensor?

I suggest you look at the answer to http://answers.unity3d.com/questions/11413/mario-kart-style-car-physics

(And when us smart-alecks let up, there's google. :-)

Is this about your car or is this about Unity3D...?

The real question should be: How to get 11 points of reputation doing this?

Real Answer: Sell Saab. Buy Volvo. It's a lateral (cross-grade) , not up-grade. However this is only because it's impossible to upgrade from Saab ownership. With the change left over, buy a cardigan in gray to offset a light pink and white check shirt. Tan Corduroy pants, knee high socks and excessively mountain orientated footwear. If you're not into cardigans, a suit jacket in some mustard colored variant of brown with overtly brown elbow patches should flesh out the ensemble.

You're going to live forever in a Volvo, so take up smoking.