Brake dust is actually more of a reason why you need to do this type of car maintenance. Brake dust is basically a mixture of adhesive and carbon fibres that are generated every time you drive. This dust comes off hot and it is highly corrosive which if left on the wheels it can cause them to rust and eventually render them useless.
More at …… https://diyautoservice.com/cleaning-aluminium-wheels/
MG ZT info mods and maintenance 