Hi
I have a similar problem.
The birth date on my NIE is wrong.
I have bought and sold one property and bought another using this NIE over the years. No problems. Try to register a car - no can do due to differing date NIE/Passport.
The NIE was obtained originally by a lawyer in Mojacar.
Do I have to return it to Mojacar, or can I do it locally (Orihuela) when I am next out?
Ted