Theres no need to buy bolts from VW, the allen key fitments are a rubbish idea. Ive used 17mm headed bolts with the same tread and lengh which should never cause a problem if you have to have them off again. If hammering a socket on doesnt work then grind the head off. Its easy to remove the thread once the carrer is off the car buy putting in vice. You might need to remove wheel bearing nut and outer wheel bearing so you can remove the disc at the same time to gain clearnce while you remove the carrer. Hope this helps