I don't care what anyone says....I think Ford really missed out by not doing their own version of this. Absolutely amazing design and idea. Hope you get it Hanky...it'd look awesome with your cars stance.
IIRC it was JMS that used to make this kit. They had a few little idea's that did ok, but not enough to keep the company afloat. The "instructions" given, also stated that this SHOULD be done by an automotive body shop because doing it yourself could turn out horribly.
Excellent idea in theory, execution could be disasterous.
Meh, I've cut, welded, spliced, fabbed etc; and am pretty darn sweet with bodywork. Between myself and a few talented friends I'm not too worried.
Considering most people can barely install the basics; and from what I used to have to deal with as I 'was' the professional shop...I'd be afraid to sell a person a tack on spoiler without a disclaimer.
JMS had a lot of problems with getting that kit to work. They leaked a lot and without the proper cage setup in the car, it was buckling the roof. I've seen that car they use as the example in person and that one was done right. I saw another that was not and it was absolutely horrible. It would have take an experienced shop quite a lot of effort to fix its problems.
Enter at your own risk on this one dude. Ever since one years ago i wanted to do this but after seeing that disaster, i've decided against it.