sirius/xm retrofit

[albertchampion]

i have a 2006 215 coupe. it has every option but satellite radio.

i would like to add that to this car.

my benz dealer tells me that at one time, i could have done that.

but now, benz will not supply the parts.

anyone know how i might acquire the parts to add that satellite reception to the oem radio/cd player?

thank you