Now Richard... buying a BMW is a bit of an expensive method of getting into our karting team, cant you just bribe Nigel !
The car is a good choice.. just make sure it wasn't on of the 'bad' ones that suffered premature engine wear. (BMW blamed the high sulphur content in British fuel).
... if you buy a car that has been kept in the 'system'.. (supplied and serviced by authorised BMW dealers) then your friendly service advisor should be able to track it down and verify the history.
If the car you want needs a second opinion, you can have it checked over, again by your local dealer. They will give it a thorough going over and report on any shortcomings.. this service is not advertised, again you will need to chat up your service advisor... it is a lot cheaper and more thorough than the equivalent RAC/AA inspection.
Insurance wise... our club scheme is run along the same lines as the one you are used to with TVR. We don't use Flux anymore.. we have changed to AON. You will find that quotes are competitive, but importantly you will get cover for all 'club' activities including rallies and track days.
If you would like some blurb on our trackday at Croft, give me a shout.
Regards
Nick Wright