Bike Rack for Pickup with a Trailer (not 5th wheel)

I've seen those. They are intended for short distance, low speed shuttling of mountain bikes and not general transporting. That's why its called a shuttle pad. A couple of good bounces at freeway speeds will still do nice some damage to your tailgate.

I made one with PVC pipe. For less than $35 including the tie downs.
http://www.utahmountainbiking.com/goodies/TruckbedBikeRack.htm