Well, anyone with half a brain can tell a kit from the real thing. Mostly the kits are based on the wrong wheelbase and don't have mid engine etc. You can also tell by the fit and finish, sorry but a $30,000.00 kit doesn't even come close to a $400,000.00 lambo or McLaren.
There were a few manufacturers who made body retrofit kits for the fiero because it was all bolt on. Some of them looked really hot in their own right. Since they stopped making the fiero I don't know what's still available.
Just remember that for just about any car on the road there are many body kits available. I'm not talking about tuner kits with wild spoilers etc but there's some that just make the car a little more aerodynamic and a little sweeter to look at. I know Roush makes a deadly kit for the mustang and others.
Now the car doesn't make the man, and any woman who is into a man because of what he drives really doesn't have much character but hey, if you only want em for a night of fun, who cares right?
Now choosing the right car for YOU is important. For eg: Most women see a middle aged bald guy in a optic yelllow corvette as pathetic, not hot. But put the same guy in a DB9 or Vanquish, and IMHO that spells success...(which is a turn on for chicks or so I'm told). Same goes for a bright red convertible mustang, that's just plain wrong.
Now if you want to turn some heads the classics are coming back big time. Nothing like a fully restored charger in black, with a big block rumbling under the hood to catch a few eyes.