I'm really impressed with the vehicle class. In the end, it wasn't as complicated to set up as it first looked. I'm seeing two strange things happen though.
1. Gravity seems slow. Other objects tied to the same PhysicsSimulation behave and look correct (I've set gravity to 20f down), but the vehicle acts like gravity is much less. This might not be what's actually going on though, because…
2. There's no steering! Either that or it's having almost no effect.
Overall it feels sort of like the car object's physical simulation isn't being updated frequently enough. Can this happen, where it somehow updates less frequently than other bodies in the simulation? What else could be causing it?
This is how I call updates to Integrate():
public void Update(GameTime gameTime)