What are most desired ramps for loading bike into truck or what is the least expensive trailer (and size ) to carry bike? DAQ?

I have a 4x8 Harbor Freight special trailer. You add your own wood. Folds up too! I've put two dirt bikes in it but only one street bike. It'll run all day at 65mph.
Great little thing!
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90154

http://www.harborfreight.com/cpi/photos/90100-90199/90154.gif

thanks MarkG ,I will look into that.