Some time ago, i found a TM PowerUp demo and i installed it!
One thing i found different is the desert car, that has a strange engine sound and a quite different physics. (Maybe easyer to drive )
Also you found these differences?
The powerup demo was the first TM I ever played. Yeah i noticed the differences but I actually like the old physics better than the new ones lol. Do you still have the demo link? I'd love to play it again