I leased an Audi A6 2.7T a few years ago. And, have considered leasing several BMWs. I did not go the leasing route on my BMW.
Leasing can be a great way to go, and in some regards I can see as less risk in owning the car.
The key items when leasing a car are the Residual Value, Money Factor and agreed Sale Price on the car. The later is the only one I was able to control. I was told the the other 2 were driven by the banks...but I dont know if this is true or not.
When I leased the Audi it had a residual of 51% on a 3 year lease. This is always off the MSRP price. The price we agreed on was about 8K below MSRP or 4K below invoice. It was the last year of the A6 with the 2.7T, they had the new A6 comin in shortly.
In the end I felt like a did the right thing leasing the car. The car was actually worth less than the 51% according to Edmunds. To me in the end I lost less than if I had bought and was trying to sell the car.
If something was wrong with the car, or was damaged in an accident. That would bother me, and I know I would just be turning it in the end. This was less risk to me. I cant imagine selling an Audi or BMW that has been in an accident. It would be a turn off to most buyers.
I can see why Audi monthly lease rates are higher, their residuals are typically lower. And, that is what you are paying is the difference between sale price and residual. The math is pretty simple.