Last year I had to change my distributor cap because it got cracked and then rain got into it. Since the car would barely really run, I went and got one at Wal-Mart. One thing I noticed was that the metal inside was a silver colour (probably aluminum?), unlike the Bosch one I'd been using (copper/brass?). Is there a difference in performance comparing the two types? I'd think copper would be better since it's a better conductor, but the voltages are so high that I wouldn't think resistance is that big of an issue. However, I know that VW also specify silver (better conductor than coppper!) spark plugs, so they do seem to be picky about certain things. Comments? Thanks -Dave