nitpick: apt-x hd is a lossy audio codec and is almost never the source encoding of the music. most people are streaming aac, vorbis, or mp3, which is transcoded on the fly to apt-x hd. this is a lossy-to-lossy transcode which is basically never going to be transparent. apt-x hd is not a "quality signal" unless you happen to have a bunch of flacs on your phone.
I understand. what I'm saying is, nine times out of ten, the audio files themselves are already going to be in a lossy format. it's not really practical to have lossless content on your phone or stream it over a mobile connection. the lossy-to-lossy transcode is going to sound bad enough that most people would notice in a double blind test. this isn't some mp3 v0 vs flac audiophile nonsense; lossy-to-lossy transcodes sound noticeably bad.
from your other comment, I see that you are using a pretty good DAC in your car. kudos to you, sir.