Hey guys, awesome site you have here. Just recently bought a 4.6 in Florida, and drove it home to Ohio. I absolutely love it! Has some minor issues, the usual stuff that needs to be taken care of. Hope you guys have some advice for me. I'm wanting to upgrade my nav system, maybe the head unit itself. How do I know if I have MKIII or MKIV? What would you recommend for an upgraded interface. Any help appreciated....

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