In order to work with a vacuum door lock system, you need a keyless entry that can be programmed for a 2-3 second hold for that function. Almost all have that feature. In addition, you need to wire together a pair of 'Bosch' relays to trigger the vacuum pump. Easy. As long as you have a new enough Benz to use an electric vacuum pump, any competent shop should be able to wire in a keyless entry. If they refuse, keep looking.
You know, that might be an informative way to get a competent installation for any car - ask about a Benz first, even if you have a Buick.
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