New 2011 GTI, whats a good sound system?

i just bought a 2011 GTI, with the Navigation. and i had 2008 mustang before and my stock sound system was beautiful on it. it had enough bass everything vibrated and shook. and sounded very well. the stock GTI system sounds horrible, the max volume doesn't even satisfy my need for loudness that's not ridiculous. I want a quality sound system that give it that extra "oomph" that will make me fall even more in love with it? if not what sound system do you use or recommend?