When I bought my TC, the previous owner had just added a set of glow steps. He mounted them to the rear face of the bumper and added an extra step on top of the bumper. They are rock solid.
They are mounted so well that hanging off the bumper didn't bother me except for the small 1/16" cable that keeps them folded while traveling.
I added a 1/8" x 1" aluminum bar with a slot cut in one end that is bolted on to the top step. When folded, it slip over the eye bolt on the bottom step similar to a door hasp.
That keeps me from needing bungee cords to keep it secure on ruff roads.
The small cable became a lanyard for a spring clip to secure the "hasp".
"hasp" from underneath. Obviously missed washing the algae off the back of the steps:

Top step is mounted with a 2" stainless lag bolt on each side:

There are two rubber Reese 2" hitch covers mounted where the original step hangers are that keep it from hitting/rattling on the bumper.