Here is the Remote Control Parking retrofit from BimmerTech which includes the display key. It's only $100 more than the key itself. You do have to have comfort access, surround view, and parking assistant for it to work. Remote programming is required, but is included in the price. I'm thinking about pulling the trigger even though I don't need it!
https://www.bimmer-tech.net/shop/bmw...rking-retrofit