With not-so-good experiences with the Alloy Gator Rim protection (see this thread) and disappointment with the other commercial alternatives available (cheap plastic devices that provide almost no protection) I came up with my own method of protecting my rim edges from curb rash and other sources of scrapes and scratches. I call it Rubber Rim Bumpers (RRB). Rubber Rim Bumpers consists of rubber cord glued (with high quality superglue) to the concave area on the tire where it grips the rim. Rubber Rim Bumpers provide several times the protection of the Alloy Gators and other commercial products and cost 1/5 the amount. They're also easier to apply and remove, blend in with the tires, won't show dirt or abrasions, and work with 21" and 19" wheels of any kind. The rubber cords are readily available online and and only need to be applied whenever the tires are replaced or removed. They can also be applied to tires and wheels that have been in use. On my Michelin Super Sport 21" tires 3/8' rubber cord fits the concave space perfectly, providing bumper-like protection for the rim. The rubber cords are Buna rubber, an artificial variety with very good abrasion resistance, compression rebound, chemical resistance, and other specs. The rubber cord is available from Grainger and is sold in number of sizes. The cord is also available from Ace Rubber. The cord is available in colors (made of silicone). As each brand of tire is different, other sizes may provide more effective protection. For example, on the 21" Continental tires a 7/16" or 1/2" rubber cord will work better. I started installation tonight and will finish it tomorrow. The first step was to thoroughly clean the edge of the rim and touch up any superficial scratches with Tesla's rim touch-up paint. I then careful used duct tape to tape the 3/8' rubber cord around the trim to measure the exact length needed then cut it to that length. I used that piece to measure and cut the pieces for the other three rims. As the rubber stretches and compresses a bit, perfection here is not necessary as the final perfect fit can be made on the wheel with a little stretching or compression. The two photos below show the concave area on the tire next to the rim edge that the rubber cord fits into. These next photos show the rubber cord taped into place so that I could determine accurately the proper length. It's not clear in the photos but the rubber cord in this position provides at least a 3/16 barrier outside the rim edge plane. When I glue the Rubber Rim Bumpers into place on the tires tomorrow I'll clean and dress the tires then post more pictures. I'll also deliberately scrape a curb to test them. I'm that confident.