Aftermarket CID?
 

I just got a 2005 X3 3.0i without nav/or CID. My question is that if I can install a CID on the dashboard without the nav unit? All I need is the LCD display on the dash (just for fuel consumption info) If this is possible, how can I connect it to the car? I have the retro nav installation document but I just want to make sure if I can do this without the nav unit. What the total cost would be for used items?

Thanks.

You need something to 'drive' the CID display. This can be either the Navi computer or a BMW Video Module. The 'radio' has nothing in it to drive the LCD and you would just get a totally black display.

For the cost of a 2nd hand Mk4 on ebay, surely that would be the sensible route? The CID radio can be bought off ebay too.