jaykay,
I just checked the Bentley and the M490 and M680 radio/amp wiring is identical except for the add'l lines from amp to DSP actuator panel (for MY'00). So the good news is you should be able to drop in a M490 amp eliminating M680 amp and DSP panel provided there are 3 plugs on your amp (one each for DSP panel, input from h/u, power & output to speakers). Please confirm.
Plus, still need to know if your rear speakers are wired to the amp or head unit - pretty sure it's gonna be amp. To confirm, look at the physically largest plug on amp (or plug w/ largest wires). Are pin locations 5, 6, 15, and 16 empty or filled (should be a 20 pin connector plug)? They will be two pairs in the middle of the plug, a pair in each row. If filled, which I'm pretty sure they are, they should have a white, white w/ brown stripe, black and a black w/ brown stripe colored wires in them. As such, you will need to find a 6 channel M490 amp to drop in (mine is only a 4ch). If they are empty, then the rear speakers are being driven off your head unit and if you have 3 separate plugs mine will work. We can talk off-line to test as such, etc.
For speakers, I recall using Infinity Kappa 4.25" coaxials in the dash and 6.75" in the door (only connecting woofer in doors b/c these amps have a built in cross over). I had the upgraded PNP rear speaker kit not the OEM one. The rears, like in a home theater set up only provide surround so it's not imperative they be of high quality as they just draw the music towards your ears in the seat as opposed to it being pulled forward under the windshield.
Good luck
Threaded Mode
