I SOOOO recommend you switch speakers there buddy. I put Alpine Type * 5.25" 2-ways and Infinity Reference 3-way 6x9'* in the rear of my old 98 SSE with the Bose and it sounded beyond incredible.
The sound stage was WAY improved and the quality and the cleanliness of the upper db range was such an improvement that people I know with some big systems in their Grand Prix'* (that were factory equipped with BOSE) were swearing I had switched out the factory BOSE amp also.
You will not have to get speaker wiring adapters as the Bose speakers had them installed from the factory.
Here are a link with a couple pics from when I did it (I didn't get any 5.25" pictures but the front'* have the wiring adapters too -but with a screw to secure them to the center of the magnet):