Good one. Yeah, that's what happens when the BMW's genetic code gets all out of whack, multiple fin!!!!
So you probably notice the three (3) fins on my E60. In addition to my OEM rear deck spoiler and sun/wind deflector for my power moonroof, there's that shark fin on the roofline.
This fin is actually the car's antenna for GPS/NAV, Sirius Satellite Radio and BMW's Assist program and their TeleService feature(where the car actually calls your local BMW dealership for scheduled maintenance service, followed by a phone call from the dealer's service advisor for an actual service appointment date/time).
At first, didn't like this fin. But got used to it over time. Take care!
Umnitza now provides a mechanic to install all parts ordered right in the box! It's their new "Total customer service program" that will eliminate all the haters and keep incompetents from breaking **** and blaming the vendor! When you are all set simply call INS and they will pick him up free of charge.