So I know EAC uses the lame.exe for wav-->mp3 conversion, but how does it burn audio CDs from mp3s? Does EAC do the conversion? I don't see lame.exe opening that's for sure.

And what about BAO or Burrrn? Do they do the audio conversion or is there something I'm missing about going from mp3 to wav?

The process is similar for all those programs: they work as front-ends of .exe decoders. So the program "send" the mp3 file to the decoder, and then the decoder does its work generating a wav file.
Edit: And when we have WAVs, we can burn the CD Audio. Burrrn and burnatonce use cdrdao, and I think that EAC uses its own burning engine.

Burrrn uses lame and burnatonce uses MAD external executables for MP3 decoding. Don't know what EAC uses but I am pretty sure it is "built-in" rather than an external exectuable.

Everyone seems to agree that lame is best for encoding to mp3, but the next logical question is which decoder is best? And what _does_ EAC use? Anyone?

I'm trying to loose as little of the quality going from ripped wav-->mp3-->audio CD compilations as possible. I want mp3s for my poratble, and audio CDs for my automobile.

There is no difference in quality with current decoders.
All of the suggested programs should will decode just fine (as long as you are feeding them properly encoded --LAME-- files)



But there is one small thing: GAPLESS MP3

Even if there is no quality difference between decoders, you will want your MP3-sourced audio CDs to be gapless, right?

There is only one decoder (AFAIK) that produces gapless WAV files from MP3, and that is the foobar2000 decoder.
So I suggest that you try foobar2000 and whenever you want to burn a CD from MP3, decode them first to a temporary directory using foobar's diskwriter (you can also adjust the volume on this stage) and then burn the resulting WAV files using your preferred software.
It will take slightly longer, but you will be very pleased with the results.