[vilord]

Also, I totally get this project. Is it worth doing? Nah, but it is partly just about the project itself.

Got an F series HK/L7 amp + E series L7 speakers for $150 from my yard including the last 3 feet of the L7 amp cable so I can join it to my car. (my car came with the standard 10-speaker e91 "hifi" setup. I'll be converting it to an 11-speaker setup for now, to include the underseat subs, front-door and rear-door mid+tweet, and center channel. will add the rear mid+tweets later, since it requires pulling down and replacing the headliner in the e91, and finding an l7 e91 headliner is near-impossible locally)
Another $100 for the dash-mounted idrive button panel, the console-mounted idrive wheel already mounted in the right wood-grain LCI idrive frame (non-touch for now, maybe i'll add touch later), a usb jack for the glove box, a usb/aux jack for the center console, a usb glovebox cable, and a second bluetooth antenna to use with the wifi jack for apple carplay.
Bought an apix2 screen, black top evo, and ATM from ebay for 700.

I have the retrofit adapter from bmwnbt.com... we'll have to compare how well this one works against your CarSystems adapter.

I also bought a usb -> CANBUS adapter so I can send the correct wake-up signals from my laptop for bench testing. And amazon sent me two of them by mistake. If I get it to work, I can send you one of them.

Once I get a working CID cable I'll start bench testing to know what connectors I'm still missing... probably swing by the yard again next weekend to cut out the terminals for an ATM if I can find a yard with a new enough car.