OnStar FMV Available July 24th At BestBuy For $300

  GM's aftermarket rearview mirror with OnStar FMV built-in is hitting BestBuy July 24th.  Expect to pay $299.99, plus $75 for installation and $18.95 per month.  The mirror will work in most vehicles and there is an online compatibility configurator here.  Not sure how I feel about another recurring monthly…