(By the way this is my absolute first time working with constraints in this way)
As shown above, this simple car goes flying when going over this ramp.
The car wheels use both Cylindrical and Spring Constraints.
After disabling each and testing it seems that the Cylindrical Constraint are the problem.
The settings for both constraints are almost default along with the masses and custom properties of the objects.
I can supply images of the properties if needed, thanks!