does your m5 have nav, as most US spec M5's do? I have the radio unit from my 00 M5 from when i upgraded to sirius. I can take a look for it this weekend to see what the p'n is. I'm not sure if there is a specific radio for 'eurospec' cars, as when i installed the new radio unit in my car, it was set to 'euro' mode, so my sirius didn't work until i set it to 'USA' mode. It also went thru radio stations at every 0.1 set, rather than staying on odd numbered frequencies, as we have.