I have one also and the best thing i can tell you is go to this link about the blower fan...
http://www.unixnerd.demon.co.uk/bmw_home.html there are a lot of links to different places there, but from my reclooection it is a transistor assembly on the fan itself. As far as trhe speedo, there is a plug on the rear end which is the pickup for the electronic speedo. if it is the odometer bavauto sells the little plastic wheel for the inside of the speedo assy for about $24. The trip computer has a small fuse in the control box in behind the glove box that blows about everytime the car is jumpstarted, replace it and it should work... got any pics??? i love mine and would like to see pics of the one you are looking at.