Rigidbody, Front slides toward Gravity down Hill

Let's say I have 2 rigid bodies attached (parented) to a cylinder object, one on the front and one on the back. The object is sitting on a hill or moving on hill. The cylinder object is laying down parallel to the ground, much like a car is setup. How would I use gravity to move RigidBody2 facing toward the downward slope of the hill faster than RigidBody1 so I can orient the vehicle in the right direction without forcing the player to have to manually use controls to orient the rotation?