Model collissions and anchoring!

How would I go about making parts not fall through the floor while having can-collide set to false and anchor set to false? I need this for my go-karts but every time I attempt to do this they fall through the floor.

I think you can use the collision groups property to change what parts can collide with what

Why would you need this for a go-kart?

Either they need to ride on the ground using physics with at least the wheels Cancollide true, or you need to move them using scripted CFraming, which would keep them off the ground that way.

I use physics (CanCollide true Parts) in my Suspension test game, try it out to see how it would work for you.