Did you see RJsfishin's receiver mount for his modules? I don't remember in which thread it was pictured but I thought it was a pretty elegant way of mounting.
Lifting two 30 lb modules that are joined by hinges to any appreciable height would not be a task I would like to do on a regular basis. I would rather have an easel on the ground or even one of BFL's turntables to use for securing them in position. Actually, I wouldn't want to do either, if I could park in half way decent sun. Roof mounting is a one-time shot and keeps the modules out of harm's way.