I can't stop regreting everyday that I did not get the navigation in the new TL. Does anybody know if it is possible to upgrade from a non-navi to a navi. Thanks A lot.

 

nope. you have to trade in the NON-nav for a nav

 

This has been discussed numerous times. Search and see. Very expensive to do. You are better off trading in and getting a new TL with Nav.

Worst case get a dash mounted unit.

 

As those members mentioned above, it's hard to convert it. If money isn't issue, there is always the way to put some aftermarket Navis into your car.

But if you intend to have genuine Acura Navi put on into Non-Navi 04TL, it's much harder than having those aftermarket ones. IMO. It isn't impossible at all, but...