Trolle, you should be able to get some on e-Bay. I bought a 6mm kit from "Toolsqwik" and it came with a lot nicer insertion tool than the actual "HeliCoil" brand kit. HeliCoil is an actual brand name that everybody pretty much uses generically for "thread repair inserts", kinda like everybody calls an adjustable wrench a Crescent wrench - Crescent is a brand name as well.
http://cgi.ebay.com/20-Helicoil-6mm-X-1-00-Thread-Repair-Inserts-NEW-Tools_W0QQitemZ290114770908QQihZ019QQcategoryZ303QQtcZphotoQQcmdZViewItemThe above link was only for inserts but I have bought the complete kits from them in the past at about 1/2 of what a HeliCoil brand kit costs. If you get a 6mm x 1 and 8mm x 1.25 kit that will cover probably 90%+ of all the stuff you'll strip on a Beemer, at least did for me. I think the center valve cover stud is an 8mm or 10mm, pretty sure it's an 8mm.
For anybody needing to fix any of these center studs there is no need to pull the head. Be careful to start the drill and tap straight and use sticky grease on the tap and clean it often and you won't get any chips down into the works. But, if you are real paranoid then the head can be removed and drilled/tapped in a vertical mill which will ensure it's perfectly straight. Maybe I should market a drilling jig?
