http://www.opieoils.co.uk/c-686-bmw-longlife-04.aspx - I used Fuchs Titan GT1 Pro C-3 last time. There's a similar oil called Titan GT1 Pro Flex, but apparently the main difference is that C-3 uses fully synthetic base stocks whereas Flex uses refined mineral oil (see
here), so I think C-3 is a better bet.