To say MECP doesn't mean jack is ridiculous. Any reputable shop is not going to just completely blow off an MECP certification...if nothing else, it atleast shows an employer that you're willing to take that extra step. Does being certified automatically mean you're a good installer? No. That's where experience and references come in. Go for it. It's atleast good for brushing up on the basics and more technical side of mobile electronics, not to mention it's cheap.