lol we all wonder the same thing and im not sure joe could give an explanation lol. hes actually looking for the extended cab windows, if u look through the last couple of pages of his thread u will see some pics of where the hinges are nearly ripped off the windows.
my friend only has 2 15s in his 07 trailblazer and that thing is a piece now form it. the whole roof has beat itself off the supports and the little windows on the back doors fall out everytime he turns it up. yet he keeps addin more speakers and amps. lol to each their own