This is fantastic! It reminds me of the old Racing Destruction Set I used to play on my friend's Atari 800. You should really put some screenshots and/or video on this page, it looks so adorable :)
Hey, I don't know how helpful this comment will be, but I will put it out there. When I did play Racing Desctruction Set, one of the highlights was being able to make and edit my own tracks.
I am not asking you for this feature for myself, as I am busy making my own games at the moment. But other players might really enjoy that. I'm sure it's a monumental task, but consider adding a track editor. :)