first off, yes I searched
http://ecomodder.com/forum/showthrea...back-9490.html
http://ecomodder.com/forum/showthrea...tail-4372.html
http://ecomodder.com/forum/showthrea...rius-9789.html
on to the question.
I drive an accord and my wife drives a ranger (solid toneau cover). I would build a seperate on for both of us. I would use mine daily, and my wife would be wife like and complain, but use it on long trips. The design, however, will be similar because the trailing edges are close.
I would want it to be just slightly shorter than my trunk and extend maybe 2ft on the outside, but structurally limited to how long it could get. This would make it arched with a point at the end, and an angle of just over 45 degrees. For the accord I was thinking of some sort of 'u' shape to hold on to the trunk and then use magnets as a little bit extra.
Issues I will have is it would be right over my license plate on the accord. The truck has both a hitch and a tailgate that can be dropped to provide support.
Thanks for the help