My goodness, I didn't think it could be beaten either xD
Okay, so I finally ended up breaking it.
The last couple rounds started with the car remaining stationary at the center of the track. Speed must have been quite literally off the charts. After round 6 or so the “on gate” bonuses stopped registering, and then the game seemed to lock on round 9. I think the loop-completed sound effect continued to play.
Used the “Formuler” car, and things started to become unhinged after picking up the coin bonus per loop.

Hope this info is useful as you (hopefully) continue to develop the expanded version. :-D
Yeah, after really high scores it breaks. But I think what breaks is that "end of level" effect where you seem to recount the points achieved. Because it freezes on this screen and you can hear the "counting points" sound endlessly. So it seems it's counting like millions of points. Still, fun game!
