Are the brake dust shields a good or bad idea for our cars. I know the issue of heat build up is one of concern but is it *really* that much of a problem? I am *so* tired of cleaning off the dust build up on my rims that I am considering purchasing the shield to thwart off the accumulation. Here in Maine there are no stop and go traffic issues as was the case in Los Angeles. So would this be a deciding factor? Where can you purchase these shield? I'd appreciate opinions. Tom #05732