I decided to take my tow hitch off today. I never used it before anyway. I noticed that one of the two holes that the hitch connects to is very thin. Meaning the frame is thin and I can actually bend the metal and move it a little. The first hole where the bolt goes is much thicker. Its where it connects to the rear bumper, then the second hole further down the frame towards the front of the car is very thin. I can see the way it is designed, its thicker where it connects to the bumper. But is this normal? There is no rust on frame and feels smooth inside of the frame rail. Any help would be great.