Your canvas wheel covers or stone guards can be cleaned up nicely with Sublime Clean and a scrub with a soft detailing brush like our Plush Brush. Pre-rinse the area first, then liberally spray Sublime Clean and begin scrubbing with your brush, working in a north-south, east-west motion to better remove the dirt. As the product foams up, it will lift the ingrained dirt out of the pores of the surface.
After a few passes in each direction, it's important to rinse it all off while still wet. Thoroughly rinse the area down with your hose or pressure washer, and repeat the clean if necessary.