If the wing in question was the kit supplied one, than I would say it's not very likely though possible (depending on what sort of speeds we are talking about as well).
I have used the same bodyshell in competition but replaced the wing with a proper protoform one.
Competition-grade cars would be absolute dogs without the wings at the back. If you take a close look the bodyshells usd in competition come in a wide range of material thickness and designs as well as the wings themselves which are adjustable for exactly this reason: to adjust downforce and better tune the car to the track.
Have a quick look on youtube and see what kind of speeds we are talking about in competitions such as the ETS or similar.
And if you want to have a bit of a play, put your car on sensitive scale and use a hairdryer to blow air against it see what happens.
Team Greasy Weasel
The best upgrade to any car is some driver skill.