Has anyone done it? I want to get a new WRX with factory nav, HK, and push start but it must be ordered. I'm thinking of just getting a limited model and do the nav after market. Any insight in where the GPS receiver would be mounted? Could it be combined with existing shark fin antenna? Or would it be another bulky unit mounted on my windshield? I've seen kits that supposedly retains functionality of the steering wheel controls... Any one have experience with this and can share insights and pics?