Nice! Loved driving around and trying to break the physics.
At first I was disappointed you couldn't leave the road until I found you just needed to use more speed + boost. After that I spent all the time driving off-road.
I drove backwards at the start and clipped into some geometry, causing the car to gain a ton of vertical velocity and fly high into the air up to the clouds! When it dropped back down it bounced around a lot. Found you could reproduce this by finding where the road surface was clipped and gain some speed before entering it.
This made me think: You should add some planes!
Had a great time exploring.