Nothing will ever make the plastic trim black, new was a dark grey. You will need elbow grease, not just a coating of Forever Black or any other vinyl dressing.

I would start with a good cleanser - Bon Ami is a powder cleanser that does NOT scratch and will get rid of any left over wax on the vinyl. Follow that with a good rinse and a coating of vinyl protectant. Do this before paste waxing the car.

As for brake dust, rinse it off with soapy water. Do not rub it with a cloth or try to blow it off, the particles are so fine and easily inhaled. The dust also sticks to your skin and clothing like crazy.

Rust on the plastic wheel covers? Or do you mean the metal tabs that hold the cover to the wheel? The latter can be rubbed off with sand paper, 300 - 400 grit, or polished with a soft grinder. Then wax them. I wonder if clear packaging tape (its water proof) can be taped to the metal surface.

Of course, there is always rust on the steel wheels. I have 4 of them without tires in my garage. Not being a very good painter, I am still looking for someone to either clean them up or buy them.
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Keeping it running is better than buying new