This has come up a few times already, but I don't remember anybody having been able to successfully do this with an OE FL steering wheel. The FL steering wheel is not a direct replacement for the PFL steering wheel. The signals are not compatible, so there are third-party companies that offer retrofit steering wheels complete with a custom module to adapt the FL signals to the PFL compatible signals. There are a couple of considerations, though:
- The AMG Drive Unit as far as I know cannot be retrofitted to the PFL, so if you are looking to control the drive mode settings from the steering wheel then that's a no-go to the best of my knowledge
- The FL steering wheel has the DISTRONIC/CC controls on the wheel itself whereas the PFL has a stalk for that. The controls on the steering wheel to the best of my knowledge will be non-functional and you have to continue to use the stalk to control DISTRONIC/CC
- The touchpads on the FL steering wheel that control the instrument cluster and the COMAND system I believe also won't work quite right.
Even with the third-party replacements, those who have tried them have run into issues with the signal converter not working correctly. I've heard of issues with the shift paddles no longer working for example. Not sure if they were ever able to resolve those. There are a few YouTubers that have attempted this and they pretty much all had to go back and forward with the third-party vendor and exchange custom modules until it was sort of working. The AutoVlog guy who was on here a while back when he still owned his C63 did it for example. You can probably find his videos to get an idea.