Cars are designed the way they are for a very specific reason...the disign works and is proven. If you dink with the physical-ness of the car, you will affect the handeling aspects of the car. Only slight modificatoins if any should be done if any! If you're gonna make "adjustments" to the car, shave the parts rather than digging chunks out of them.
By shaving, i mean, take a dremmel with sanding drum and sand away making the parts thinner. But don't "cut" holes into the parts, that ruins them!
To be safe, I wouldn't mess with it!
TQ Racing Wire