Have only been looking a few weeks now and prices are a lot lower than i expected, eg There was 2black roadsters on an 05 plate at dealers near me and they were going to let go for £7500 from dealers, I let my 03 ginger go 18 months ago for just under £8k and thought i had been done guessing I would get no where near that these days.
All big thirsty cars have taken a hit this year - TVR prices were steady for years but this year there are a lot of bargains out there
Suppose one factor affecting the 350z is the 370z now becoming a lot more affordable (spoke to someone who picked one up for £15k)
Personally though I would not mind paying a premium for a "known " car but not everyone will so not an easy job selling at the moment