There is nothing wrong with used speaker components from eBay. Plenty of wrecked cars and resellers. It’s not like I’m buying a turbo off a used car with 300,000 miles.
Yes, as stated anything is possible.
I am asking if it’ll fit with the OEM harness. I imagine I’ll probably have to buy the Bose amplifier that goes in the rear and the subwoofer. Now as to whether the wiring harness is the same or not is the real question.
I honestly wouldn't put the effort into it. The BOSE sub in the spare tire well is not impressive at all. I've heard regular OEM stereo's producer deeper bass notes. Now, the staging and crisp sound from their speakers in the front? Not too shabby!