Mentioned in issue 7 of Commodore Format, a 3rd game in the Test Drive series was planned for the C64. Sadly it was never to be, as this was the only mention about the game and it soon disappeared from mention.
What happened?… What was the game going to be like?
We don’t know yet sadly, though we expect it would have been more of the same as with the sequel, with some new maps and maybe new cars. The PC version was released in 1990, so it seems Accolade cancelled things early on when deciding to move to 16-bit platforms.
This needs a lot more research and we will be trying to find out more about the game very soon.