Trailer hitch note.
 

A proper trailer hitch is connected directly to the frame or unibody of your car. This is typically a good thing, unless you are in a rear end collision, in which case the impact bypasses your shock absorbing bumper and heads right for your seat. Bumped in a drivethrough line, and my back is on fire. It may make sense to pull the ball off if you're not using it.

Sorry to hear you got rear ended moon. If you had been in some cheap little buzzbox maybe you would have left in an ambulance or at least broken the back of the seat off.
Having the ball off & the tongue still there is great. The one on my 300d sticks out over a foot. I had an idiot run into the back of me a few years ago, no damage to the Benz & a nice hole punched in his radiator. You occasionally get a squeal from a pedestrian if they try and run across behind the car without looking. Take care !!

It was the suby wagon. I nail my shin on the ball at least every other week. PO didn't maintain the hitch, fair amount of rust holding the pin in.

I'm building a 2" receiver hitch that hangs below the bumper for mine - specifically so
1) I can take the hitch and ball assembly off and
2) it will be compatible with all the 2" receiver accessories I already have...