Mesh acts weirdly

Does anyone know why my mesh acts weirdly like in this video:

The car is obviously shaking because of Roblox’s physics, and that means you haven’t rigged the car correctly, since the wheels seem to fall over.

It’s most likely because the meshes aren’t anchored.

yeah, i just want to test the body and i added a special feature is the two doors can be opened

it is not supposed to be anchored while driving on the street, i just want to test it in real world