Why are Nissan paying for your car to be remapped Do you mean the difference in cost from Abbey to Nissan means you can afford the remap? You do realise any warrenty on your engine will pretty much be null and void should anything go wrong with the engine and Nissan find out its remapped? Whether they can prove it was down to the map or not, you'd have a real fight on your hands to get warrenty work done
Saying that, I would go to Abbey and have the remap and risk it
Looking at the fact tha jerry is goin for a P1, I doubt the cost difference is £350-ish to pay for the Abbey re-map, unless I missed something.
And yes, the re-map will render the warranty null and void, because the car will have been altered from factory specs and not run as Nissan intended.