First, they are not 100% rubber and are not durable at all. I can't name the exact material but they tear easily and are not intended for anything other than a very clean install. They also don't stay in place due to the very soft material. In my opinion, they are not for cars.
Edward Tools Grommet Kit Rustproof
9 Review
CargoLoc 82473: Secure π Your Cargo With 10 High-Quality Grommets
11 Review
π§ Efficient Handheld Grommet Punching Machine by BIZOEPRO
10 Review
Cal Hawk AZGA125 Grommet Assortment Electrical: Complete your Electrical Projects with Versatile Grommets!
9 Review