The company that sells them are called Armster as I'm looking for a central armrest and they have this video of their website, thought it was quite amusing
I've thought about it but they look too unsightly, I nearly came a cropper on the works car park the other week being in the M140i as forgot how long the doors are and parked next to a wall, swung the door out and realised the worst immediately and grabbed it before it smacked the wall. I couldn't believe how close I came to making a mess of the paintwork. Perils of using a city car as well with short doors,