Pg 29 of EM.pdf (from the service manual available on this board) has the exploded diagram for the "Intake Manifold Collector" as they call it, which is the upper air intake plenum and the throttle bodies attached to it. It doesn't appear any coolant is routed into the plenum itself, but you can see the lines that go through the throttle bodies. I've marked them up on this copy of the diagram (C & E are water/heater hose connections to elsewhere):
While the intake air cooling effect of modding this is probably minimal, once someone comes up with a neat little solution for it, it will probably be $3, making it still good bang for the buck. Just need a bypass hose hooking C directly to E, completely remove various soft hoses (6, 7, 15, 16) and possibly the rear hard line that connects 16+7 (if it's not welded to the EVAP hose that runs parallel), and put 4 little caps on the throttle bodies' inlets/outlets.