Does your car have the feature where you can command all windows and sunroof to close by holding the key in the door lock in the lock position? (referred to as convenience feature) If so, you can build a timer relay that is triggered by the remote. I did this for my cars.......I can provide schematics/details if you have this feature.

J. M. van Swaay

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1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles