I just got done with my wheel well painting the idea i got from the how to. I think it turned out pretty well, what I did was i cleaned them with simple green and then sanded them to scuff them up, cleaned them with alcohol and masked, then i painted.
I used the Duplicolor undercoating, i guess it's similar to the undercoating used in bryanjwilson's how to. It wasn't too hard to paint with.
Half-way masked off, i covered my whole tire before i painted
Here it is with a good coat of it on, it's not dry in the picture, but it evened out pretty well, and it's all the same shade now that it's drying.
Great mod, now i'm off to painting my rear axle and my frame and tbars etc.