I like the 350Z interior, but that doesn't make it any good!
I also dislike the 370Z interior, despite the undisputed increase in material quality. Truth is, nobody can touch Audi for interiors (the mk3 TT ) so everything else is just acceptable next to them.
£80K is definitely a premium car though. I'd call £40K+ premium, as a rule. You could argue £30K+, but then you can get a Golf for that much now and I definitely wouldn't class a Golf as premium.