Ok been looking into this and it's more complicated than I first thought. The Bose speakers have there own amp already , that's ok but the wiring harness to the speaker has 4 wires ? Now what ? Can't seem to find anything on this . When people upgrade there head unit ( as cassettes are done with ) they have to also replace the speakers. I'm not wanting to change the actual radio or the speakers I'm just wanting to hook up a amp that I have sitting here.
I went through all the options a couple of years ago as my speaker amps were toast. I had a shop in St. Thomas rebuild my existing system and it actually sounds great! In the short term I use a cassette that plugs into my iPod but expect to have the shop wire an auxiliary jack for a iPod connection in the near future. Hope that helps. My suggestion is to find a shop that will specialize in corvette units.
I think you can tap into the rear speaker wires to pick-up the low signal.Need to purchase a converter with rca outputs that connect to the amp.Don't know how it would sound, but I've been told it can be done.
If you're adding an amp of any significance, would suggest you run back to the ground in the engine bay or the neg terminal on the battery. It will still run if you don't but May fault or over heat due to inadequate grounding. Different of course on a metal body car.
Shane, a buddy of mine is right into stereos, he built several cars and vans for comp late 80's and early 90's, he has never got out of it. We both worked at Crusin in Stereo in Guelph and the owner did his C4 so if you maybe wanna call him and talk I can hook u up with his number....he loves talking stereos lol