Keyless remote (RF) receiver location '95 A6/S6?

[Santoliquido Stephen R NNSY]

If it's the same as the 96 A6, it's under the back seat on the driver side.
The remote programming sequence is different than for the 97 and on (also
different than for IR. So be sure you're using the correct procedure before
assuming a problem with the controller. As I recall, you turn the ignition
on with one key, lock the drivers door with another key, then hold BOTH
remote buttons for about 5 sec until the lights blink. But I can verify this
for you later if need be. Also, you cannot "see" the controller with
VAG-COM.
Good luck;
Steve