I have been noticing that my gps is lagging behind, for example i passed a intersection by 10-20 feet and my avic d3 is showing the i am just passing it that moment, in other words its behind 10-20 feet than my actual position.

Is this normal thing for the avic d3 or is there a setting where i can adjust this

thanks in advance

There is indeed a setting in the navigation menus. I forgot exactly where but I believe it says "Edit Current Location". From there you can move a cursor to where you believe is the right spot for your car

Mine seems to be off sometimes. It'll be either a block off or even lag behind. Will installing the VSS wire and reverse wire help with accuracy?