Hi Alan
As of the April 2020 price list the NX Premium Pack is £ 39,315 (actually £ 39,260 for this discussion as it is minus £ 55 for first registration fee which isn't counted for the tax threshold) and standard metallic paint is £ 670, so no, it doesn't exceed £40k to hit the additional tax. If you went for the special metallic paint (Sonic White, Sonic Titanium, Azure Blue, Blazing Carnelian) then you would be over £ 40k.