The keyless entry part is perhaps easier, I put one in my '87 300D but it had no alarm so there was one less thing to worry about. You still have to buy or build a relay module to simulate the switch in the door; with that, the entire apparatus goes under the passenger seat next to the central locking pump.

I am in the process of designing a similar system for my '95 E300. As this car has a functioning alarm, I will need two sets of relays, one for the CL pump and the second for the alarm.

As Sixto has written, the remote start will be more challenging.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970