Help! Business vs prof radio (and aux input)

[CBlack1105]

I bought the auxiliary audio input retrofit kit. Dealer installed it. Doesn't work.

Then read that the reason is probably that I have the professional radio and it seems that the aux input only works with the business radio.

From what I have read, the only difference between business and professional radio is dual radio tuner capability or something like that - which I don't really care about - so would ask dealer to swap out the professional radio for business. But the dealer mentioned that the professional radio has an additional and/or better amplifier.

Does anyone know if this is true and/or any other reason I shouldn't give priority to being able to use the aux audio input (and hence Ipod) vs having a better(?) radio??