Originally Posted by Jason
WM stands for Windows Media. Windows is a computer operating system so its specific filetypes aren't going to be compatible with car audio hardware by other manufacturers. Most CD burners that I know of will convert to a generic audio CD format automatically. Make sure that's what you're doing and they'll work fine.
Actually it is "WMA" and it stands for: "Windows Media Audio" a proprietary compressed audio file format developed by Microsoft. A thorough discussion of the WMA file format can be found on Wikipedia:
WMA files can be played on numerous car audio devices (as well as a myriad of portable player devices). My 06 Prius for one, the after market Pioneer car stereo I had in my 05 HCH, and according to Honda's spec sheets, the 06HCH. (Heck I have software on my Palm TX that play WMA files) In fact, it is in Microsoft's best interest to license the technology to as many people as possible. Look on Microsoft's website for a discussion of the "Playsforsure" technology.
As for the CD burner converting file formats, are you talking about the burner hardware itself? Or, the software that controls the hardware? It is the later that actually does the conversion, not the former.
Back to the original posters dilemma, it could any of the following: Faulty player hardware in the HCH, improper bit density of the encoded CD, DRM** protected content, or ???, not enough info in the original post.
**DRM = Digital Rights Management, see: