The buzzing sound you'll get from the iPod connection cable, I assume because of no high/low noise filter. I get it too, I never used to because I have a high end JL Audio system installed (they're supposed to counteract it) but lately i get the static at low volume, and it only happens sometimes after prolonged use of the xcarlink. When I use the AUX cable I get no interference but I can't use my steering wheel controls haha. The filter won't set you back more than like $10 at the absolute worst from what I hear, guess it's something i should look into and for yourself if it really bothers you. For now I can deal with it haha