Arcade Bike Physics is very easy to use Arcade style Bike Physics Tool. You can create drivable Bikes under 1 minute.

FluXY simulates 2D fluids that look 3D, using your GPU. Can be used to simulate fire, smoke, paint, water, trails, and a variety of VFX.

Physics Based Character Controller is a feature-rich, highly customizable rigidbody based character controller super easy to pick up and use out of the box and / or customize

Fast GPU based clothes simulation for 3D Projects.

Magica Cloth is a high-speed cloth simulation operated by Unity Job System + Burst compiler.<br>Both BoneCloth driven by Transform and MeshCloth driven by mesh are available.

Universal plugin for creating linear/ bezier splines in Unity Engine

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.