Interesting ideas, Gator.
Phase change would require some kind of substance which would, of course, disappear over time, like dry ice - solid to vapor w/o turning to liquid first.
TEC, on the other hand might actually be practical, plus some TEC's will run on 12Vdc. I haven't done enough research on these babies to be sure but do they come in sizes big enough to fit the intercooler or would the plan be to place several in various spots on the cooler instead?