Anybody has that nasty black grease on their rims?...U could wipe it off but It gets dirty again within a few days. How can I take care of that?...Any products I could use?...and where does that grease come from?

 

No idea, but that does not sound good if it keeps coming back.

 

grease or wet brake dust? if it's brake dust, just don't use your brakes.

 

I think he's talking about brake dust. Just have to get used to it. I wipe it off every 2nd or 3rd day. And it's not just on the rims- it's on the whole car, mostly the rear end.

 

Mr Clean's Magic Eraser and water.

 

If the Grease is only on a FRONT rim it could be a leak from the oil cooler lines.
https://www.rx8club.com/series-i-trouble-shooting-95/leak-oil-cooler-line-58015/

 

If it's break dust you can swap your break pads to ceramic pads. It should get rid of most of the dust.

 

Simple Green to cut through and clean off break dust.
Then polish the rims with Turtle Wax Ice to prevent the dust from sticking again right away.