I don't really like 'em.
Some cars need them to look complete, some don't. Functional, aesthetic, optional, standard, deployable, fixed, factory, after-market - It doesn't matter - I think (most) cars look better without them - flame me, I've got my suit on.
Sometimes you don't know if it will work without a wing. In this case, the Zonda looks a little strange.
What do you people think? And if you've got a car you'd like me to de-wing, let me know!