ANY input is appreciated. My speedometer starting acting up years ago and the symptoms would come and go until finally it quit working altogether. The engine light is on (code P0500) and so I'm unable to pass state emissions to get new tags. A reputable local repair shop has had the car for weeks now. We've replaced the VSS and swapped in two used head units/gauge clusters, AND had a speedometer repair guy come out to go through the actual speedometer. Nothing has worked and after all this and all the diagnostics they can do, they're throwing in the towel. I just set an appointment with the local Nissan dealer to attempt a diagnostic. I know others have had better luck with the VSS and head unit replacement. What could we be missing here?