I recently took over the maintenance for a co-worker's 2008 528i. I think this one has the ZF 6HP19Z transmission. This car has 185k on it, and it still has the original transmission fluid! The transmission shifts just fine though. While BMW recently revised its fluid change recommendation to 100k, this particular car never saw a fluid change because it carried the original recommendation of lifetime fill. A proper fluid change for this car isn't cheap - $143 for a new ZF oil pan (the filter is built into the pan) and $227 for 7L of the correct fluid. Plus, getting the fluid level right is not going to be easy without the BMW scan tool. However, my greatest concern is "stirring up" issues; I'd hate to service the transmission and have it fail shortly thereafter. We've all heard of stories where high-mileage transmissions get serviced, and they coincidentally fail shortly thereafter for no apparent reason. So - would you touch it? I'm leaning towards no.