Loved those shots. What are you using to mount the cam to the car? I'm toying with the idea of mounting an XM2 with a suction pad, but am so scared the cam will be crushed against the sceneray or another car! I've been meaning to shoot footage of my brother in law and his mates sweeping past on motorbikes.
The begining shot is the classic starting grid fly around. Can look something special with a stabilising system. I just picked up my glidecam and ran around a car just now (balance wasn't quite there and I was being v sloppy (way too much bounce - arm still aches from the weekend!), but you get the picture

)
http://www.videoforums.co.uk/glidecam.wmv
What was the music?