So I just bought this 2007 sapphire black m5 6speed. I have put about 300 miles in it and it won't shift properly. The clutch is not engaging all the way so it's rough to get into gear and especially rough taking off from a traffic light. It is chattering from while taking off from the traffic light. I have had slave cylinders go bad before in my M3 and it seems like that's what's wrong again. Is this common? Also is the slave cylinder external or internal?