Aftermarket plastic wheel covers -around $30 each though
 

While looking for "aerodynamic wheels" on Google, I came across these : https://www.speedwaymotors.com/Domin...rs,242017.html

Of all things, they are used for dirt track racing to keep mud out of the wheels.

( They come in all sorts of goofy neon colors too, if that's your thing )

https://ecomodder.com/forum/attachme...1&d=1618676446

Looking at the reviews, shows that they may be prone to cracking, but I'm guessing they are more prone to do so when under stress from racing.