Sirius system
 

When I bought my 06 X5 in 09 I was told that there were no adapters available, so I searched and found a BLIZ adapter aroud $150. It is advertised as PLUG AND PLAY not expecting much I plugged it in and IT PLAYED RIGHT AWAY...HOLY S**T. CAME RIGHT UP ON THE MID UNIT AND WORKS 100%
NOW, I'm looking to trade up to an 09...some do not have SIRIUS, will my BITTZ work as a plug in, or what is necessary to get SIRIUS working.

Do these sales guys know ANYTHING?
One tells me that you cannot easily or reasonably add SIRIUS to a non factory equipped car...another says you can if the car has NAV....
Do any of you guys KNOW what is the real deal?