I'd love to have time tracking and stuff from GOG Galaxy while playing this but obviously GOG isnt selling the game anymore and I've lost my last chance by miles.

Is there any site or place that is selling keys that can be redeemed on GOG?

It is not possible to purchase the game, as the licensing for vehicle IPs had expired. You're 2 years too late, unfortunately (they had the game on sale for something like $2.).

I'm pretty sure referencing other sites would be against forum TOS.

Ask a friend if they have the game, play it that way. If you can get it running, that is (it wasn't patched past 2014 and the game still has a lot of issues running, even with modifications to XML files).

This long after it was pulled, I doubt you'd be likely to find too many (valid) gift codes for sale on open marketplace sites, or many GOG forumites who still have unredeemed codes, for that matter.
The only place I know of where you can buy a "legit" copy is Zoom Platform, whose version is also DRM-free.