Raycast vehicle
A vehicle model whose wheels are not physical bodies but rays cast downward from the chassis to sense the ground and compute suspension and grip.
Instead of simulating four round rigid bodies with contact points, the engine casts a ray from each wheel mount straight down. The hit distance gives spring compression, and a spring-damper model computes the suspension force; lateral grip and drive force are applied at the contact point. The method is cheap, stable and forgiving, which is why it drives most arcade racers — Bullet, PhysX and Unity all ship a ready-made RaycastVehicle.
The downside is that the rays miss thin obstacles and the wheels never spin against real surfaces, so dedicated simulators use fully simulated wheels with tire models instead.