was washing the car at the weekend and the alloys are a bit of a mess (OK, I'll put my hands up and say I'd not washed the car in a couple of weeks. But only if you read couple as 8 weeks....)

Anyway, one of the alloys has a black mark on it, what am I best doing to take it off? I was going to use the AutoGlym alloy cleaner I have but it was starting to rain so I had to stop.

Also, tips for getting into those hard to reach places on alloys?

I have these on my car

which are a nightmare to get into the middle of the spokes. They are too narrow (just) to get my fingers into.