They vary in design because anyone with a welder can make them out of 1" od 3/16" wall dom steel tube, and some plate.
Some are more valuable to the chassis then others but none are really "needed".
Wide fender cars probably would benefit more from them because of the added jolt to the chassis from the bigger rubber.
To me they are just glitzy techno jewelery. Wear what makes you feel good.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.