These are the ADCO covers that I've been using for about 10 years. Mine were bought before the new style (with bungee balls). Mine have two grommets at the bottom to run a bungee cord behind the tire to hold the cover in place. I've never used them and never lost a cover, so I'm not sure how strong the wind would need to be to blow one off a tire....
https://www.amazon.com/ADCO-3952-Whi...5409235&sr=8-3
They ain't cheap, but they are, IMHO, worth the extra to get something that works and lasts. I think they're the same (or similar) to the ones sourdough and ChuckS have described in their posts.