The aux input is not good but when you get your new system it will sound
a whole lot better. Also I have some doubt that a 50 dollar blue tooth aux
adapter is very good compared to some of the stuff built into a good HU or one of the better adapters like a Mobridge or Dension.
If you want really Hi Fi maybe you should look up Neil Youngs attempt at Mobile studio quality sound . He had a 24 bit device designed called the Pono
but it hasn't taken off yet.