I really don't see how anyone could mistake the Z for a Lambo or Ferrari.
Not a single model looks anything like the Z, now a Porsche, maybe. They have similar body styles, but I know as soon as you get up on the car you should be able to tell it's not a Porsche. And like LuckyJinx said, Nissan Emblem, 370Z Emblem on it??? Dead give away?! (unless you de-badge your car, of course)
Anywho, my Dad's old 1979 Volkswagen Bus was similar, only 13 year old girls and 60+ year old elderly gave him looks or thumbs up....well and hippies too.
Edit: @PapoZalsa: love the avatar pic.