hey mate understand the problem, am a mechanic myself and with you replacing everything you have to understand that your discs being shiny and smooth surfcace at first will be hard for the shows to grip onto! my advise would be to other run them for a while and bed them in or take the discs off, get some emery paper and slightly ruff the inside of the disc so the shows can grip! p.s a have a 3 series and my handbrake is the very same! hope this helps! shaun