Started up my 2008 550i & backed out of my garage in the dark one morning a couple weeks ago. Headed off down the road when suddenly the red oil light appeared on my instrument cluster & immediately went out again.
I had doubts about its validity as I had just checked oil the day before & had a full sump. I thought I must have a sensor problem. Message came on the screen to shut off engine so I pulled over. Had the car towed to my local independent German car specialist for diagnosis.

Since the tow truck driver was heading out in the direction of my house, I hitched a ride and jumped out a couple blocks away & walked home. It was now light outside & as I approached my house I saw a trail of oil leading down my driveway (see attached photo). Then I opened my garage & was shocked to find a pool of oil (see attached photo). Had this all happened in daylight I would have seen it immediately and shut off the car; but I never saw it in the dark.

My mechanic called me to say that the plastic oil filter canister underneath the car had cracked and leaked all the oil. After replacing the canister & refilling with fresh oil, he was unable to restart the car. Compression tests showed two cylinders well below normal. The engine was toast. I was devastated. Since it wasn't that long ago that I did a full suspension refresh, replaced brake pads & rotors, replaced the tires, and upgraded lighting, I will be replacing the engine rather than junking the car. I found a replacement engine with less than half my 161k miles on it so I'll be starting the New Year getting the car back in service.

 

It's taken a couple months but the new engine has been installed and the car is running better than ever. I couldn't be more pleased with the results.
The "new" engine came out of a 2007 650i that suffered an accident that did not affect the engine compartment. The engine has 85,673 miles on it but had been sitting for a couple years, so we did a lot of improvements before installing it, many of which included swapping parts from my engine. I had newer valve covers, water pump & thermostat, coolant exchange pipe, and cleaner throttle-body. We installed new valve cover gaskets, new upper & lower oil pan gaskets, a new alternator bracket oil gasket, and a mew clutch kit since I still had the original clutch at 161k miles. Also added new spark plugs and fresh oil.
I could have just junked the car but I'm much happier with the "new" version.

 

Glad to see another E60 saved. You'll have that car for another 10 years without any major issues if you want to keep it that long.