I have been looking into this for a while, but with not much info on actual cars...it make me weary.
I personally know of a person that self build one from the racks of the local Home Depot store and he is driving from Fl. to Va. and I can't wait ti hear from him, to see how it ran.
There are a lot of plans out on the net and they run from $20 to $3000.
A lot of answered questions for me to take the dip, but I can tell you that I am very anxious to do it.