I know the service techs far more than I should for such a great car. Do NOT put anything liquid in the trunk and expect not to fry your iDrive. Some idiots in Germany made the trunk porous and put the iDrive electronics package in the trunk, so if you have cooler and it tips over, immediately get out your rags, etc., and get that water out. I have fried the iDrive twice in this way, and it cost a bundle to fix it. Really poor engineering.