Hovercar-like movement?

Hi, im a beginner both unity and scripting. Basically, im trying to make a hover-car like controller. I got a gameobject that floats on a plane. How do i make the gameobject rotate/float around randomly and smoothly without using animations? I heard that you can use the sinus modifier to do this, but i dont know how to use it to rotate the gameobject around, not deforming it. How do i do this?


You might want to look at buoyancy keyword in Unity answers and the forums actually, you don't want a boat but hovering is actually a very similar behavior.