Wheel Controller 3D is a complete alternative to Unity's inbuilt WheelCollider. It allows for more realistic vehicle behavior, complete customization, and 3D ground detection.

Arcade car controller: asset with arcade car physics, well suited for mobile projects.

Pro Car Paint Shader allows you to achieve the most Realistic metallic effect for various surface paints like Glossy , Matte , Pearlescent , Varnish and Transparent surfaces like Windows, Glass etc. Photo-realistic visualizations of Cars, Motors, Planes etc within minutes.

NWH Vehicle Physics 2 is a complete vehicle simulation package for Unity. Realistic, easy to use and heavily customizable.