These aren't built in a machine shop to NASA specs. A little rattle is to be expected. The electrical tape trick tightens things up a tad. Just don't drive around with your draw bar installed and no load attached. Make the rattle count for something and be pulling a load whilst enjoying the macho trailer pull'n soundtrack.
Part II;
I have to eat my own words. Today is the first time pulling my trusty utility trailer with the Ridge. There is a huge amount of noise transmitted through the vehicle compared with my old Ranger. Two reasons I can think of. One, there is more play in the receiver/draw bar combination on the RL set-up as compared to the one on my Ranger. Two, the Ranger is a conventional truck with a ladder frame with the box and cab mounted to it. The hitch is attached to the ladder frame an is a tad more isolated from the cab. The RL hitch is bolted to the unibody undercarriage and it is a direct link to the driver's compartment.