If you've ever opened the door of a Mercedes R129, you will probably have noticed that the way it operates is slightly different than your everyday saloon car door. The windows are frameless, which, apart from looking pretty, means that when you open the door, the glass lowers slightly. Once you close the door, the glass lifts and 'seals'. The issue with the frameless door design is that if for some reason the lowering of the window does not work on opening, you will not be able to close the door properly (or perhaps you might, but I dread having to slam the door shut with such force and worry that it might break something).
The first time we were faced with this problem was when we had the brilliant idea of putting some moisture absorbing crystals into the car while the battery was out. Yes, you can use the physical key and unlock and open the car door that way, but after that you've got a bit of a problem. Had to put the battery back in just to be able to close the door - luckily it was charged by then... So, a piece of advice from someone who learned the hard way - if you have taken the battery out of your R129, limit the opening and closing to the boot of the car.
The second time this issue occurred was just recently as we left the house at 5am to go to the airport. The air temperature was a balmy -3C (you would have though that with all the smog and exhaust fumes it shouldn't be possible to get sub-zero temperatures in London, but there you go) and, apart from frost all over, the passenger window froze solid to the door and didn't drop on opening. Completely unprepared and not even able to find a scraper for the windscreen we then had to sit in the car with the heating on for over 20 minutes, trying to lower the window at regular intervals. Advice here - either budget time and wait for everything to unfreeze or, as clever people on forums (interestingly, BMW and not Mercedes) recommend, do not forget to refresh the silicone grease or gummi-pflege coating on the seals. We have only put silicone grease on once in the time we've owned the car, which was a very long time ago, and I think it's probably time to refresh it.
