A week ago I bought a new 2006 Civic EX coupe. When I bought it, the salesman said that the total cost of adding XM radio option was a little over $900, installation included. Or I could have opted for the Navagation model, which includes XM radio... for about $1700!! I want XM radio, but I can't see spending that much money just to add the XM tuner package with harness etc. Is it less expensive to have a car audio store add the package to my XM ready stereo system? And what about getting the antenna that matches the body color (alabaster silver)? Who makes the factory installed Premium audio system for the new Honda Civics? Any Recommendations please!! I want it to be compatable

Joe