Do any of the current generation of MP3 players deliver source quality adequate for relatively nice car and home system?
Most any MP3 player will do quite well in delivering high-quality sound. What will almost always be the deciding factor is the bitrate that was used to sample the sound when it was converted into an MP3. For MP3, the higher the bitrate the closer it is to the original quality. The encoder used also has a big impact on quality. You may have to experiment a bit to figure out what works for you.
Compression is the reason I've not made the jump to MP3 players before. I would absolutely be sticking with .wav or a lossless format. I really don't think I want to go any smaller than 64 Gb for that reason as well. I could go 32 Gb if I had too and I could just rotate music according to my mood. Rotating music was one thing I was hoping to get away from though.
I think I'm just going to have to buy the best stuff I can find and try it out. I'll most likely pick up a iPod Classic (160 Gb) and then update my car's head unit to something with full iPod controls and the D/A conversion on the head unit. Toys sure get outdated quick these days.

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