For those of you that have the Piecha Varioroof Module, I want to alert you to a possible complication that you may experience if you ever have a dead battery or need to disconnect the battery. I did not start the car for a couple of months, and the battery was completely flat. After charging the battery, when I opened the driver’s door a malfunction message immediately appeared (even before I got in the car or put the key in the ignition) indicating a problem with the roof, and that I needed to take it to the workshop. As you might expect, the roof would not operate. I also noticed that the windows no longer pulled up tight against the roof gaskets after the doors were closed, and I figured that also had something to do with the roof malfunction. I tried disconnecting and re-connecting the battery several times hoping that somehow whatever was detecting the roof malfunction would reset itself, but that did not work. Before I took the car to the dealer, I wanted to make sure that the roof module was deactivated so that the dealer would not realize I installed it and claim the warranty on the roof was not longer valid. However, the usual deactivation procedure would not work, and I assumed that it was because the car had already detected a malfunction with the roof, and would not allow anything associated with the roof (such as the windows or the module) to operate. It looks like my assumptions may have been correct. It appears that the roof goes through some sort of diagnostic procedure when you open the door. I tried leaving the drivers door open when I disconnected and reconnected the battery, and sure enough, there was no malfunction message when I reconnected the battery. I got into the car, deactivated and then reactivated the module, and now the module as well as the roof seem to be functioning normally. Has anyone else experienced a similar problem?