The way I see it is this: Anyone who knows so little about cars that they would be fooled by it wouldn't notice or care. Anyone who might actually care will spot it a mile off.
I remember having this exact conversation with my mate getting on for 30 years ago when you saw XR3is with RS Turbo badges on..
Even half decent conversations stand out a mile, I used to see something claiming to be a Focus ST on the M3, good conversion with all the right badges and wheels and exhausts, the lot.. stance was all wrong, like it was on stilts.
It's always baffled me, I get tasteful mods.. not outright trickery.. I mean especially when its medium cars, don't you spend more on making it look like the thing than you would on the thing?
Bentley Chryslers and especially Ferrari MR2s excluded from that obviously!