I realize this is a pretty old thread, but a bump for a really nicely done how-to thread...
I was searching for some ideas on amp mounting and wiring for my setup [ipad mini / pioneer head unit / polk speakers, documented here
The only thing I'm not completely comfortable with is drilling the sheetmetal for the amp board. I'd much prefer to use factory bolt locations, but it doesn't seem like they are in good spots. If I do drill, I was thinking of installing rivnuts just in the sheet metal instead of through bolts. Would eliminate that grinding/sealing you had to do on your mounting bolts.
Thanks for the ideas and good documentation!