I've heard of folks swapping in a GM chime unit for the buzzer on here before but can't find a thread . FWIW the buzzer is just a piezo-type element that applies circuit to two disks (one usually copper or steel, the other ceramic) and the resistance causes it to buzz. Used in reverse, the same principle is used by microphones, and I have tons of piezo elements to use as pickups for my electronic drums. Cost: about $0.25 a piece, a buck or two from radioshack with the plastic "buzzer" housing.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth