As the title says.
F8x style sliding armrest. No idea why this wasn't stock in the US!
Purchased from ECS tuning for $220 + shipping, and waited a month for it to come in from Germany.
Used for about 2000 miles - only selling since I replaced this with an M4 armrest.
Utterly mint condition. Not a mark on it. Looks brand new. Simple, 5 minute install, and - especially if you're short like I am - revolutionize your interior.