It was actually a class-action lawsuit with a 1y window to get it inspected and fixed, which expired in 2010. Sounds like that's around when you got yours done. I just picked up this car, so I'm a little late to the game here.
I just called Erhard FH and the guy did say it would be out-of-pocket, but maybe I could lean on BMW NA to get it comp'd? Never had to schmooze my way into a recall getting fixed, so I'm not sure what kind of leverage I have.