The front of the car, intake for the radiator, would be the only place to put in a screen to protect the radiator or the AC condenser. These cars are low and a lot of stuff gets thrown up by other cars. I made mine out of stainless mesh and installed it to deflect tire rubber and rocks on track.
Be aware that any screen here will restrict airflow by at least 10-20%. BUT unless you are marginal on cooling, DUE TO AIRFLOW VOLUME THROUGH TO RADIATOR, then it shouldn't be much of a problem. The inlet on the car is plenty large in cubic inches to feed the radiator. These sort of problems can most always be solved by sealing the inlet to the radiator so all the air going in the inlet goes through the radiator. Just something to be aware of should cooling issues arise.
As far as the side inlets. I don't believe there is any direct threat to rocks etc getting in that way and damaging anything. I do suppose that different people would like the looks. So be it, to each his own.
Let me dig mine out of the boxes and I'll post pictures. We can go from there.