The best guys in town.
I went to these guys after i had stereo problems caused by another installation company. Not only did they fully check all the electrical components, they even fixed some of my old speaker which i though died years ago. This trip only cost me 45 dollars, compared to the other in town (best buy and audio express) who both wanted to charge me 100 dollars just to look at it. I definitely refer to these guys for all my car audio needs in the future.