yes drop in but might need to move a few pins/wires around in the harness. They have the same master plugs as I recall and are same dimensions. I'll try and consult my electronics schematic over the weekend (or you can yours if you have a Bentley manual). M490 was an option side by side w/ M680. M490 was first but carried through the MYs too until '03 when all went to MOST/Fiber Optic set ups. You can upgrade all the speakers and still keep it looking stock (I did on mine). The OEM amp is decent, not great, but ok. The speakers truly are absolute junk... of the grade you'd find in an AM alarm clock radio from a Dollar General Store (and yet I've insulting Dollar General w/ that comment - LOL).
