Try Going Wingless
Do you really need that rear wing? If you’re running on a track that has long high-flow sections, your wing will provide some downforce and give you extra traction. What happens when you run on a smaller track with short corner-to-corner sections? Yes, the wing is still going to provide some downforce, but in this case, it may not be providing extra traction. Remove the rear (and front if you’re running one) and see if your vehicle still gets around the track with no issues. Not having a wing will reduce overall weight, lower your vehicle’s center of gravity, and reduce drag, which, in the end, can make it faster.
Take the wing off your vehicle and see if it handles as well as it did with it on. If the performance of your vehicle doesn’t change, then run without it to save weight and reduce wind resistance.