Amazed by Blue Tooth finally.

I've done comparison in my car audio (Subaru XV) USB hookup vs. blue tooth and blue tooth won in almost all: transparency, clarity and dynamics. Will blue-tooth benefit home-audio components same way vs. let's say coax digital in or USB? What is the good blue-tooth preamp nowdays if any?
this is unusual because Bluetooth by its very definition has lower bandwidth than USB. An audio file requires more bandwidth than Bluetooth can provide to provide CD-like quality. Unless your Subaru has aptX technology already built into it? aptX technology has been the secret weapon of Bluetooth for some time now - it's a codec that compresses the music file so that it can fit into the Bluetooth bandwidth while not sacrificing CD-like quality sonics.
Bluetooth is good for short distances such as 30-50ft (which is definitely the domain of the automobile).

Dont know of any Bluetooth preamps but the latest all-digital amps NAD 1030 & 1070 (which they demo'd at RMAF 2013) are BT capable.
Another British brand is Chord Electronics with their QBD DAC (I think I got the model correct?) that is also BT-capable. in later models BT was dropped because it was deemed quirky & not many people used it as the SQ was not very good (opposite of what you are reporting!).
You can send your data to these devices & in one case you can directly drive the speaker & in the other case drive a conventional preamp. There must be other brands that are BT-capable. The key, I think, is to have aptX technology so that you dont sacrifice SQ.
Not all USB implementations are equal. It is very possible that the USB in your car was a low grade install, regarding audio. Bluetooth vs USB battle in my "reference" 2 channel system was won by USB, but I am unaware of truly HQ Bluetooth components, if they are out there, lemmie know please.