Bit of an annoying issue i have...so when i'm washing the car i always use a wheel brush and some wheel cleaner to scrub the tyres then rinse with water...it gets rid of most of the dirt but im still always left with some residue!
The only way of masking it is to use some tyre dressing but sure that fades after a few days and im left with a clean wheel but with dirty tyres! What do people use to clean their tyres??