A rectangular object or decal that applies a force to a vehicle above it. The force would have a direction along the length of the object. This would be legendary
I understand, and agree that this shouldn't be included in the realistic part of the game, but instead a part of the gridmap. Alternatively, just something one can add in the editor. Perhaps this would be a task more suited to a modder if the game allows this kind of modification
As much as I like trackmania, I don't see how this would work. Modders have posted alternate engines, with more power than you can use. Unless the booster hooked right into the speed of the car instead of adding power to the wheels, it would be useful only for spinning out, I'm afraid.
Well the game has gravity, so one would merely need to create another localized field of gravity rotated 90 degrees
I would imagine gravity is pretty deep down in the physics. Probably deserves a "One does not simply create localized gravity." Also, something that changes the way the car behaves in a fundamental way might break as the game gets updated. Time will tell
Or we could see if there is a console command to (Temporarily) change the cars Max RPM/Speed if someone is so inclined to go at the speed of sound in a van.