'92 300SE - Got the car without any remotes. Found one on e-bay that's the proper part # for the car.

Attempting to program the car to accept the new remote and still doesn't work.

New batteries in the remote, and I do see the tell-tale LED when I hold the button down for a few seconds.

AllData doesn't have any valuable testing methods - any other suggestions?

There's another '92 300SE in the parking lot here at work. I plan on contacting the owner to see if they'll let me use their car for a test mule.