Originally Posted by signes
About 38k right now.
We've seen the same on MY08s, just had another one last week with gains of ~16whp after updates were applied. If the vehicle was purchased used, there is a chance no updates were ever applied or worse - an early performance tune loaded with no follow-up diagnostics.
A VIN check with your dealer will show maintenance history. Since you're the original owner - this is a bit easier to backtrack. BMW reprogramming for electrical gremlins doesn't necessarily mean the DME was touched.
Check the condition of your plugs and have the DME reprogrammed with the latest updates (v2.46.x) and dyno again with a new tank of fuel. It's certain your lost power is within one (or multiple) of those variables, assuming dyno procedures were properly followed.