I solved traffic!
It's a little glitchy sometimes, pretty sure some of my solutions were not the intended ones! I got stuck a lot too, and sometimes the other cars in the puzzles would refuse to move, even if I wasn't blocking them with the race car. But niggles aside, it's a very enjoyable twist on a classic puzzle game. I haven't seen anyone attempt to add new mechanics to this sort of sliding-block logic game before.
I found I had to Austin Powers 48 point turn quite a lot. That could possibly have been solved by letting the car continue to turn while blocked by a wall. Similar to the way it can slide along a wall at an angle. I don't know how many puzzles that would break, mind.
I'm also not convinced it fits the theme perfectly. It's not exactly a role reversal - more a role extention and genre mashup. That's not to say I don't like it. I thorougly enjoyed my time solving all 14 of the levels! If the other cars say, moved when they could, rather than it being your choice to drag them around, that might have been more on-theme.
Congratulations on creating a lovely working finished game in 48 hours. No easy feat!