So I recently purchased a 2002 Volkswagen Jetta off of a friend of a friend. Today, I played some music and the sound quality was horrible!! :/ It sounds muffled and shaky.. I tried to adjust the treble & bass but that didn't make a difference. I want to have a new system put in, do you think it'll fix that problem? If so, what exactly do I have to get? I don't know anything about sound systems or cars lol.. What brand do you reccomend?? Thanks!!