No relationship with them (other than using their web site as a useful way of getting UK dealer prices when I have a part number!), but I see that Coopers BMW are offering 10% off all parts and accessories from 1st August to 30th September 2012.
Full details at http://www.cooper-bmw-parts.co.uk/home/ (and it's UK only).
Full details at http://www.cooper-bmw-parts.co.uk/home/ (and it's UK only).