I have not, but first you need to find a good trailer hitch IE one that fits.

I have a 1x1 reciever that will end up on my '80 to use for a bicycle carrier but it's gonna be custom made to bolt to more than the bumper like most Pinto hitches did.
 
Unless the motorcycle is under 250 pounds I wouldn't trust it hanging off the rear of the car because it's gonna squat & the front tires are gonna lose most of the weight that gives you stability, especially in turns. Maybe a V8 car with new heavy leafs out back.......May be.
 
I'd pull a trailer instead, especially if you were thinking 500+ pound street bike hanging 4 to 5 feet behind the axle centerline of a 2600 max. pound car. An XR80 or 125 maybe but not a street bike. I hope this helps.   

I'd use the 2"x2" reciever for that kind of weight. The bar going into that will be 18" long at least & 150+ pounds bouncing down the road will bend 1"x1" easily. You also want to avoid excessive welding to the reciever bar since heat will weaken it.