Linear Damping just for Z velocity?


So I am messing around with physics, trying to make a decent hovercar / speeder bike. I was wondering if there is somehow any way to split up linear damping on an object into x, y, and z, or manually re-create a damping effect? Id like to be able to dampen the change in the objects Z velocity without affecting its X and Y translation.

Heres what I have so far, (notice the hovercar bounces a lot, which is why Id like to dampen it).