I've heard of guys putting radios from higher end buicks circa 2000 in their fwb's. they look factoy (because they are), have CD and tape, and IIRC a 200 watt amp. you could always mod the radio to put an 1/8 inch jack into the outputs from the tape mechanism to the radio itself. I know it can be done on the 1.5 DIN radios as well as the old 2 post style, so I don't see why you can't do it on the newer radios. no dremel required, just a solder gun.
btw, you shouldn't need a $50 wire to bypass the tuner box. run new speaker lines, new ignition and constant power lines, and a ground to the new radio. its not hard, just time consuming. leave the tuner box as is in the trunk with power.