Have purchased used parts on eBay to get the scroll wheel. Is Tesla planning on selling part separately?
I see it in the parts catalogue with no discernable way to buy it. If I'm missing something here then by all means call me an idiot and point it out.
Unless you have an unsupported vehicle (gray market or salvage title), you should be able to walk in a Service Center with your VIN and purchase the part over the counter. It's a hassle that you can't buy parts online, or call and have the parts waiting for you, but they will sell parts to any owner of a supported vehicle.