No, from what I have seen, +4's have problems in ANY car. I have yet to see a car get more power or MPG out of a set of +4s. (platinum or normal +4's)

The theory behind the +4's is that the spark will always take the path to least resistance. If one electrode get's carboned up, it will jump to one of the other 3 electrodes. Only problem with this theory, is that if one electrode is carboned up, more than likely they ALL are. Also the 4 prongs of the +4 plugs tend to "mask" the spark, which can lead to slow/improper flame front travel.

Thanks Random, I'll pull mine and take a look at them this weekend, (probibly clean them)