When fiddling around with Street Rod 2, we found that - after a certain modification - the game is starting in what it calls a Demo Mode that showcases several parts of the game. Usually that demo mode is not being launched and we did not find that it triggers in any other way.
If someone knows more (we just did some quick tests honestly), hit us up. Its nothing special, but we still wanted to document it. You can download the game for free from our archive page: https://archive.org/details/street-rod