Ever since I purchased my E55 I've experienced issues with it jerking when pulling away and also rumbling (like going over a rumble strip in the road) under light acceleration. After a bit of investigation I came across all the threads regarding coolant getting into the transmission fluid and basically wrecking the torque converter. I understand that the Valeo radiators are the culprits and can be identified by toothed end-tanks. Is this one (my rad): If so, I wonder if this explains why the previous owner of the car had the trans fluid flushed not long before getting rid of the car. I'd imagine fresh fluid would help mask the issue for long enough to trade it in?