Having fans on the intercooler is a terrible idea. I've seen rally cars pull fans off the front of radiators before as they simply restrict flow when they are not on.

Putting fans behind the intercooler to draw air through would work when not moving, but you'd want them to be awesome fans and engineered for the cooler. When doing 100kph, i'd be worried about the i/c working propertly due to the fans directly behind it.

Waterspray is still the go. I just run a Hobbs pressure switch @ 15psi hooked to washer bottle. Run a few sprayers and you're done.