You're right Frost, If they want scientific results they would do that, but I think the reason they don't is these are anecdotal observations and not part of the criteria by which they are rating the car.
I'd bet a more thorough investigation would find that the noise levels between the coupe and the roadster vary depending on the road conditions. I'm willing to believe the roadster is quieter on a smooth freeway -- the soft top is nicely lined and there is a separation between the rear of the car and the passenger area, but noisier on rough roads where some shudder from the slightly less stiff chassis can increase noise
Anyway, there's too much hullabaloo about 370z road noise. It's like most reviewers of the 370z almost feel embarrassed by how much they love the car that they have to say *something* negative or the critic in them dies just a little bit
