HD Radio has a fourth automaker out of the closet and announced in the digital broadcasting camp. It's Mini, which is offering HD Radio two ways: as a $500 standalone option, or as part of an audio upgrade package for $1,400 that also includes better speakers and Sirius satellite radio with a lifetime (of the car it's in) subscription.

Mini follows BMW, its parent, in offering HD Radio on current models, but only if it's built in at the factory. It's available on the current-generation Mini Cooper and Cooper S hardtop models introduced this spring but not the Mini Cooper convertible, which is an older design. BMW also charges $500. Jaguar has announced it will offer HD Radio this fall, also at $500 (great minds think alike?), and Hyundai says HD Radio will be offered on an unnamed luxury sports sedan due out in the future. Translation: It will be offered on the Genesis show car when it becomes a production car, most likely a year from now.

Genesis is Hyundai's attempt to move further upmarket into the entry reaches of BMW, Lexus, and Mercedes-Benz territory. By 2008 other automakers, as yet not announced, should also be on the market and we expect HD Radio pricing will drop swiftly, to the point where some savvy automaker will swallow the incremental cost and include it in all car radios.

HD Radio provides one to three digital stations: one is a digital simulcast of the analog AM or FM broadcast also on that frequency, and the other one or two are separate programming, with no analog backup. The digital broadcast is considered to be much like listening to MP3 music in-town, though the signal doesn't carry as far, so in distant listening areas you'll be switched back to the analog signal.

In urban areas, HD Radio is a passable competitor to satellite radio. With HD Radio, you don't pay a monthly fee, while with satellite you don't get bombarded with commercials. For now, HD radio for the most part doesn't have commercials on its second and third channels, but that's likely a near-term phenomenon.