At the time I remember there being loads of different cars available, and it seems there were. The toys were a re-branded version of a Japanese toy line called Choro-Q which are still made today in Japan.
It seems that the Early Learning Centre has the license in the UK now and sells a modern version that looks roughly like the old line. I guess it's an ideal cheap toy line that they can sell for pocket money prices.
The cars are pretty well made and considering the small details and fiddly bits they can take quite a battering. The pull back action was always a favorite of mine as a kid. I loved the Jumpstarter transformers that flipped open as they traveled along.
There was another pull back car I had that rather than using a penny to make it do wheelies, came with a small metal weight shaped like a spare tyre. If anyone can remember what those were called, get in touch.