You can't do a full postcode search. Only the first part then it will list all the streets etc in that postcode area and then you choose from the list the exact one you want. Not a very good search system actually.
Many of the places I visit are in the middle of nowhere, up single track roads. A full seven digit postcode search generally puts us within a couple of hundred yards from where we ought to be. Four digits covers miles and we have no street names to get us closer.
I had a Chinese set up in my old BMW, it did Bluetooth, USB, DVD, Rev camera and always got us to where we wanted to be for £400, it even had Freeview,
I'm not impressed with Lexus at all