Hi Mark,
The holes for 2 speakers additional are already cut........ on the carpeted section below the rear bench seat, toward the outside edges. Push on the carpet and you can feel the holes cut into the wood. I think I have pictures of my 1998 202BR with the speakers installed.
Also, just an FYI, the entire bench seat is hinged along the front edge....tipping the rear bench seat forward gives you a lot more room to access the engine. To tip the seat forward, grab the back board behind the seat back cushions and pull up/forward.
Phil Belcher
2003 266CCR
496 MAG, Bravo 3