This is really cool! Thank you for making/posting this. I played around with it for about half an hour to 45 minutes or so. I did manage to break it two or three times but I can't reproduce it reliably yet. I'll provide a proper bug report if I can figure out the exact conditions, but mostly if you go off road and get to the top of a big enough hill and then accelerate down the hill as quickly as you can and crash into a barrier you can sometimes flip yourself over it. When you do, you are no longer tethered to the ground and, instead, kind of hover above it and the road. Sometimes you can slip through the ground and the water, and all other barriers become passable.

https://i.imgur.com/YDyJa5g.png

(edit: It might be related to hitting slightly awkward terrain?)

(edit 2: Got it on video, though my commentary didn't get recorded for some reason) https://www.youtube.com/watch?v=f7U-qS7P2tI