I Just got a pair of ramps from TSC for $79.99 each. Their plastic and
retract from 4 foot to 8 foot. Have a slight arch for taller trucks and
they also have side walls to keep your quad from falling off the sides.
They come with straps to clip to the trailer hitch to keep the ramps from
falling off the tailgate. Check them out at: Highland Ramp Champs.

I love them and they have a picture on their site of a Yellow Rubi (that's
what I load) on the back of a truck. The ramps retract inside of themselves
and fit under my rubi. They can hold 750 lbs each ramp. Couple of other
places have them.