I did this myself today, was hard to get the bolt out without disassembling alot of stuff, but managable. The shavings were soft aluminium flakes from the middle cover and plastic from the top cover. The bolt was not too damaged, meaning it didn't drop many flakes of hard stainless steel. I guess I was very lucky that bolt didn't hit somewhere hard. But I did stop the engine as soon as I heard the knocking sound and never started it again until fully cleaned up. The bottom plastic cover has 3 top screws, but it partially lays behind the largest wheel that rotates the generator belt. So I could just bend the plastic in order to get the nozzle with compressed air inbetween, then used a small telescopic magnet to capture the bolt. It took a while, blowed at many different angles, and finally it got stuck. Then total cleanup with alot of compressed air again, moving the camshaft manually by hand, centimeter by centimeter. The belt looks good, so I'm skipping the replacement this time, don't really have 1500 euro to throw away right now. But yes, if the belt got damaged, then I might be fu*ked up at some point 🤦♂️ Also contacted local VW dealer here in Sweden, asked if there were any recalls on this issue - nope, nothing on recall or guarantee list. Fu*k them! =)