Guard for toad

I think it depends on the road .. normal roads I noticed no damage ,or at least minimal, until I did 10 miles on a hard but graveled Road.at25- 35mph( what all the other traffic was doing lead car construction zone ) My car was covered in gravel (wiper recess) on the front of the hood and lower plastic bumper fender panel were pitted badly. My Journey had Good mud flaps behind the wheels and a rear full flap across the rear.about 3- 4 inches off the pavement