Actually looks pretty good niko, only problem is that you should take 2 different images, one with the car, and then turning off the follow car option from the Shift-u menu, then one without the car to hide those ugly edges from the car. You'll have to cut out the car and the shadow from the 1st pic and put the 2nd image as the lower layer to make it work, the only problem is the smoke in this case, but it is possible to brush the smoke quite easily. Just look around google for smoke tutorials. Good luck
Had another go @ the screenie mentioned here , you can see the new outcome *here* ( 2,06 MB , 1600*1200 , PNG ). Surely someone will discover where the idea behind the edit came from
Comments are highly appreciated !