Closing Assist/Door Lock Issues Due to Pneumatic System Problems on Mercedes-Benz S600

This car is a sunday driver but has been sitting for a while because of the high cost of fuel. I recently noticed that the power assist door were not pullling the doors tight and now realize the trunk desck is also not being pulled tight. I would like to know where the part on the car is to fix this. This is causing humidity to enter the cars cabin and trunk areas. Which in turn will turn into mold.

Oh the list can go on and on. I still have not fixed this problem though. My driver side doors have about a 5-10 second delay when I shut them before they vacuum close. I also have keyless-go and the door handles on the driver side only unlock it and only sometimes. On the passenger side the door handles only unlock the car 80% of the time, and will sometimes lock probably around 10% of the time, and the other 10% of the time the buttons on the door handles are unresponsive. I think it is about $500 per door handle to fix. It is at the bottom of the list of things to do currently. I can live with using a key and waiting for my door to shut.

Have replaced all four window regulators over a three year period. This is somewhat expensive per window.

The compressor that controls rhe trunk and door assist and I think door locks and perhaps the headrests in the rear had to be replaced. This was expensive and I think about $1300, mainly for the part and about an hour of labor. I later found listings for rebuilt and/or used compressors wirh guarantees on ebay for about $200...and wish I had taken that route.