So, finally got my ass over to BMW and had this installed.
And now I have cruise control!!
My car (99 323i) was manufactured in 09/08, so it uses retrofit kit # 65710016106. This consists of:
01290016107 - Installation Instuctions
01290017969 - Stick-0n Label
32346753943 - Sport Streering Wheel w/multi function buttons
61120016012 - Retrofit cable set, speed control
61131367599 - (6) cable straps
This whole kit is $784.88 Cdn. from BMW parts department.
I already had the instructions and steering wheel (and airbag - 32341095767). Figured I didn't need the label and straps, so I told BMW to order the cable. It was $50.60.
The instructions say the install should take 1 hours. BMW quoted me 4.5 hours, but ended up doing it in 2.5 hours.
They had never done one of these before, and had their doubts that it would work, BUT IT DID.
The radio buttons on the steering wheel don't work, but I have and aftermarket unit, so I didn't expect them to work anyway...
So yes, this can be done!