Im not a fan of the manual ones, but the auto ones are nice. The earlier 5 speed boxes go wrong. Bmw say they are a sealed for life box, but only designed to last 100,000 miles?! The 6 speed box's fitted to the later models are much better and dont seem to fail. But obviously, as its a beemer, turbo failure is common, so get cleaning your strainer! Also check for rear diff noises on the road. Only ever had them go on petrol models tho?