I'm not 100% sure, but I don't believe your car has the convenience feature.

Convenience feature was an option (option code 88?) available on later model 124s

You are correct--there is a module associated with this feature. In the case of my 94 and 95 E320, it is located under the rear seat squab on the drivers (left--USA) side.

This module also handles other functions, Im not sure if it could be easily retrofitted......

Out of curiosity, where did you get this infra red unit? Somewhere I read that this option was only available on cars delivered in Germany.

J. M. van Swaay