I'm thinking of doing some audio upgrades over the winter while I save up some money for my cam...but I don't know where to start. XM yes/no. I already have the Alpine CD-7875 which is XM ready, but I still have to buy the tuner, etc...Speakers, I've got the factory...previously I've always like Infinity...but I haven't heard much of them lately...subs...amps... I honestly have no idea. Anyone recommend me to a good shop that won't try to sell me shit I don't want or need? Thanks.