Welcome to the dark side....

Check the auxiliary penumatic systems:

• Close assist. Push each door closed gently and the car should suck them in and seal them. Same thing with the trunk.
• Central locking. Lock/unlock the car with the remote and make sure all the locks operate at roughtly the same time.
• Lumbar support: With the key on, muve the lumbar support wheels on the side of each seat and verify they inflate/deflate properly.
• Backup assist: If the car is a pre-facelift model it will have two small antennas that pop up out of each rear corner of the car when you put it in reverse.
• Rear head rests: Press the switch on the dash and the head rests should drop down so you can see better when backing up. The S600 and some S500 models came with electric headrests that could be raised and lowered by the driver, but most just had the pneumatic "down only" kind.

Also, check the sunroof operation. The W140s have insulation in the sunroof cavity. It looks almost like fiber board glued in with tar. After time and hot weather have taken their toll, the glue softens up and this insulation falls down and prevents the sunroof from opening.

__________________
"It's not about how fast you can go, but how well you can go fast."

Bob in Richmond

'97 S320 (LWB), Ruby Red Metallic, 73k miles
'97 S420V, Smoke Silver Metallic, 155k miles