I just bought this 2004 E55 in October of 2019. And I had a couple times where I was making a left turn and couldn't resist hitting the throttle. Well, the left front tire would lock up hard, and not let loose until well after I had let off the throttle. So here I was looking for speed sensors swapped front to rear until I realized, that at some point someone had changed the ABS module. It still had the yellow paint pen marks on it and I had looked at the brake lines and it looked like they were in the right locations. But that's what I get for thinking. Google is your friend!
So far most of this car's problems are due to the previous owners messing with it, and not wear or anything like that. Though it does have the fuel tank leak that I guess these cars are famous for and now it's out of the 15-year warranty. Oh joy.

How it looked when I got the car.

How it should have looked.


The super awesome flat spot that resulted from the 30-foot skid as the traction control tried to get the left rear tire under control by locking up the front.