So… it has less effective mass than it otherwise should?
Then it has less contact surface area with the ground… it has less mass pressing down on that less surface area, and thus has less traction and control.
This is an unavoidable physics problem.
Like, technically, Superman has a magic ability to alter the surface tension / tensile strength of large objects he lifts… because if he did not, he would simply puncture them, or they would collapse around where he is lifting them.
I think we can assume ‘slightly hovers’ means in a magical sense where it still functions and drives like a normal car.
Given almost all the rest of the upgrades are physics-defying there’s no reason this one shouldn’t also be.
So… it has less effective mass than it otherwise should?
Then it has less contact surface area with the ground… it has less mass pressing down on that less surface area, and thus has less traction and control.
This is an unavoidable physics problem.
Like, technically, Superman has a magic ability to alter the surface tension / tensile strength of large objects he lifts… because if he did not, he would simply puncture them, or they would collapse around where he is lifting them.
You’re gonna need better defined magic.