I have a 1992 300TE 4Matic Wagon with power door locks. I was wondering if it would be possible to add a MB, or aftermarket, keyless entry? If so, where could I go to get it added and what would be an approximate cost. Thanks.

1962 MB 220SEb "Fintail" Sedan
1963 Vespa VNB4T
1992 MB 300TE 4Matic Wagon
1995 Subaru AWD Wagon