Decided to pull my carbon filters out of my 550i, so I started in on the left right filter box. It's a little wonky to get at everything and get the filter out, but not too bad. Buttoned that side up and started in on the right side. Start removing the screws and realize that none of them are threaded in, just sitting in the bosses. Look further and the airbox filter cover is about 1/4 to 1/2 inch from being seated down on the mating part. Look further and find two more torx screws that hold down various bracketry are loose as well. Notice the the connector adjacent to the MAF has the mounting clip broken off and is floating free. So prior to my purchase, this car had the CP done at the dealer and they missed all of this on re-assembly. Luckily under 1,000 miles have been put on the car since then. But picked up a noticeable amount of HP/TQ now that all of the air reaching the engine has to pass through the MAF.
Summary, check the dealers work whenever possible...
