The pins on the SLS don't unscrew like that, or at least I can't get them off like that. I just don't like the cheap plastic look. Honestly I would rather delete them because only reason you would need it is if the battery died while you were in the car.
Yeah, just have to cap the hole somehow. But you would have to remove the door panel to access the mechanism and remove or relocate the cable. I'd rather go the lazy route and replace the pin with a nicer looking one.
It's funny, I've switched the door pins on all of my AMG's and never thought of doing it on my SLS. on the sedans, the front doors screw off easily and the rear door require you to pull really hard (I used pliers) and they pop off. The new pins should pop back on, but I've had difficulty in the past with a couple of cars and ended up using super glue to hold them in place. Maybe the SLS pins are like the rear pins on the sedans? I'm sure your dealership would do it for you for a ridiculous amount.
Do not pull those off with pliers. One of mine was damaged on delivery from the trucking company and I took it to the dealer. They had to take the door panel off and change the whole assembly. It took about a week for them to get the part from Germany IIRC.
Mine is the gull wing so those things are black plastic. I think David's are the metal looking ones but he has a roadster. I guess they have to dress up the roadster somehow. LOL