eNBT classic adapter is on sale from bimmerretrofit for $345.
http://www.bimmerretrofit.com/store/...product_id=105
I think these are vin locked so once you register them with your car they can not be re used on another car.
3 years ago , i did non i drive to cic + combox retrofit. for the last couple of months i been thinking about going to EVO, but just cant justify spending money on this especially on enbt adapter.
I made my own canbus devices using an arduino that can wake a cic or nbt units on the bench for testing.
Like you said, hard to justify spending that much money on nav upgrade for to 1/4 of the cost of the car.
cid voltage regulator can be made cheap if you already have nbt to cid cable. Voltage regulator i believe drops voltage from 12vdc to 7.5vdc