Found this sight, http://mazdagear.com, that has complete mazda install kits for 34.80 plus shipping.
Product Description:
Includes PhatBox Digital Media Player, DMS (Digital Media Storage)Cartridge, DMS Docking Station and PhatNoise Music Manager. (Not compatible with satellite radio or iPod integration module) For use with PhatNoiseŽ Car Audio System: Part# 0000-81-Z05A
Product Details:
Manufacturer: Mazda
Manufacturer Part #: 0000-81-H01
That would be a great deal if it includes everything listed in the description. However, I'd [quietly] check to make sure the info is correct before ordering - that same site has two PhatBox versions for $588 each, and the descriptions for those say "Requires installation kit: Part# 0000-81-H01". So I think the 0000-81-H01 is just the mounting bracket(s) and cable(s). Looking at some other Mazda dealers, the other sites seem to do a better job of saying this is just the installation kit. For example,
this site (scroll down to near the bottom of the page).
Edit - yup, there's enough left on the carcass of the PhatNoise web site
here to explain that it is just the install kit:
Installation Kit for 2005 Mazda6 Sedan (0000 81 H01) - Includes:
Mazda6 Sedan Wiring Harness
Mounting Bracket
Mouting Hardware
Installation Instructions
The best deal I've seen on new PhatBoxes is when VW / Audi dealers were blowing them out for $119 back in 2005. Unfortunately, that deal is long gone, but systems turn up on eBay every now and then.