I saw on the BMW USA site today that they are now offering HD radio as a factory installed option on all 2007 cars (manufactured after March '07). I have an "07 335i Coupe (pre- March 2007) w/ Sirius installed. Are there any after market HD radio kits? Not sure I really want it but just curious. Thanks.

you could try going to www.realoem.com and putting in your vin... then searching for retrofits under the audio section.

JVC, Panasonic, and Alpine each make one with a built-in tuner. There also exist many HD-ready decks. Try Crutchfield.com.