Dale, could you take a look at your factory headunit for me? I'm curious if it lists on there who made it -- Mazda's had Panasonic, Clarion and Sanyo make its factory HU's in the past, just curious who makes ours.
I did NOT have to cut the rear support bracket to fit my AVIC U310BT so make sure that yours won't fit before you cut anything. I didn't fit at first but once I moved the wiring harness out of the way it popped right in.