Align non physics vehicle to angle of floor without using normals

Hi. I am trying to align a non physics vehicle to the same angle as the floor. I at first used normals but this has undesired affects when going over things like speed bumps. I have tried lookatrotation but that only gives pitch and yaw. I only want to get pitch and roll, yaw is controlled by the vehicle. I have a location I get from a line trace at each corner. I want to compare this to a part on the vehicle (that is perhaps at floor level) to determine what pitch and roll I need to apply to the vehicle to align it to the floor or obstacle I am driving over

Here’s what I did:

The vectors in the math expression are the impact points of each wheel.