[Fot] George Wright's TR4 on Britishracecar.com

[Bob Adams]

Christian,

The sidebars are called "NASCAR door bars" since that's where they
originated from. They're VERY strong and extremely effective at keeping a
car out of the cockpit in side impacts. Looking at the pictures, the cage in
George's car meets and even exceeds the current SCCA rules by using NASCAR
door bars on both sides.

You probably don't see them often in Europe. I think in Europe you commonly
see a x, that is boxed in where the two tubes intersect. You might also see
some additional tubing leading to the boxed in x section.

Hope that helps.