Mr Red wrote: Nero 8 and a different burner - that audio CD plays on a car stereo

You're referring to a CD-DA - Compact Disk Digital Audio - here? Compatibility with CD-DA is a different matter to CD-ROMs. ISO 9660 filesystems only apply to CD-ROMs. Pure CD-DAs do not have a filesystem or even files, just a set of tracks like an LP. Originally they had no metadata but 'CD text' was added later.

There are also hybrid CDs which looked like a CD-DA to a CD player but revealed other stuff when put into a computer drive. (An early one I have is 'Wake the Vaulted Echos' - the Bellamy box set - which includes, IIRC, an html 'website' and tracks in RealAudio format.) I wonder if any of these 'extended CDs' are still being released?

If burning a CD-ROM I can't see why Nero (which I admit I know nothing about) should care whether a file is mp3 - it's just a file. If burning a CD-DA it has to have an mp3 decoder to convert it to PCM - and that required a licence until recently. Any CD-ROM player would have to have a decoder too; I had a car radio (on a boat) which would play mp3 and aac but not mpc - which I had a lot of.

The trouble with stripping ID3 tags is that media players - at least ones in computers - increasingly ignore filenames and directory structure and just index the tags. ID3 tags come in various versions - ID3v1, ID3v2, ID3v2.1, ..., so you could opt for an old version to increase compatibility, or maybe the extra fields of the later versions would be useful for your sound files.