There’s nothing wrong with making a copper wire spider web inside the roof of any vehicle that has a “fiberglass top” such as a Jeep. Although many professionals use copper tape or metal sheets, this has been the tried and proven method used by many communications installers, especially for those VHF /UHF commercial users such as the police that desire an antenna on a particular vehicle that has a fiberglass roof or trunk. I assume you were talking about those that would apply the same method on a metal roof. That would be silly. I just wanted to clarify the difference.A couple trends I saw here some 20 years back...always brought me chuckles:
1. Removing the headliner and making a copper wire “spiderweb” inside the roof a car.
2. Running ground wires off all the equipment in the car and into a five gallon bucket of rock salt with a section of copper pipe in it.