I'm a complete noob to audio...

I'm planning on purchasing a AVIC Z2 for my STi. My questions are these:

Is it possible to have and be signed up for XM Live Traffic Navi updates alone, and not have to pay for XM radio?

Are there 2 seperate adaptors for each XM hook-up or just one for both?

Do you get a discount for signing up for both?

Thanks for the help in advance...

You can just get the Navtraffic, its $9.99 a month I believe, if you have XM audio its only like $4.99 a month in addition. You can buy XM audio only boxes, but not Navtraffic only Boxes, so if you want the traffic you have to buy the combo box...