Figured I'd share something I have been working on for my side business. I've designed grommet sets for 19 different race car chassis now, and I have a few more pending orders for them. These are ones I did revisions of tonight and the ones I revised on a car body. They're 3d printed in a flexible plastic called TPU so you can wrap them around the bar and then rivet them down.
I make a $20-30 royalty for each set that gets sold.