[dasmueller]

I know this does not answer all your questions but, for your car from a sound quality perspective it is not all that important as road noise will keep one from hearing the little nuances of uncompressed audio files from my experience at least. Then the other consideration becomes storage space and whether or not it is an issue. Do you want one version of a show/album or multiple versions due to various listening conditions. I for example use MP3 versions on my MP3 player due to external noise issues. Otherwise the bulk of my music is in FLAC format.

For downloading purposes I prefer SBD, Pre-FM, FM and MTX recordings as the quality is generally better. When you get back to stuff from the early 70s and before it becomes more of a crapshoot. Listen to samples when you can.

There is a good deal of useful info here-http://etree.org/ Some of it is out of date but it is worth looking at, especially the wiki.

Have fun.