I have also painted wheels (w/tires mounted) using the Rustoleum metallic
silver. Look in the Eastwood catalog for their wheel masking kit which sells
for $25.00- it's nothing more than a piece of metal roof flashing with a
couple of clips. I had roll of roof flashing from a roof repair, so it
basically cost me nothing. Take the flashing and wrap it around the rim,
overlapping by a few inches and then cut. Fit it back on the rim, getting
the edge of the flashing down in between the rim edge and the tire, and
secure with masking tape where the flashing overlaps. Paint that rim, then
move it over to the next  rim. Oh, the wheels do need to be off the vehicle
to do this. Worked like a charm for me.   Jeff
Jeff Stewart
1977 Westfalia
1974 S. Beetle Conv.
http://www.geocities.com/busnut4277