mixing years

i would like to know on average: Do people get turned off with mixed year cars or do most people not even care?

what i mean by mixed years is say you have (for example) a 67 barracuda and it has say 68 taillights and 68 bucket seats and you open the hood and there is a sweet engine in there but the air cleaner is a 72 trap door unit. Say it has rally wheels which is not correct ....lets go as far as maybe its not even a year correct color. Maybe it has, EV2 orange from the early 70s. and so on and on.

Do little details turn people off to the car (say its not for sale, just at a show) or am i over thinking this whole thing.

what do you think??