Janis, I suspect there are a couple of things that you may need to improve.
First, the stock UT intercooler is a little small; it worked fine on a stock UT engine that was located in the front of the car with lots of airflow, but your engine is larger (which generates more heat), and located behind the cabin with little airflow. So you may benefit greatly from a larger (and more efficient) intercooler. Especially as the boost levels go up (as the other guys have said, it will get hotter not cooler). It seems a lot of discussion about IC size and efficiency is based on measuring the temperature of the air going into it vs the temperature of the air coming out of it, and comparing the exiting air with the ambient temperature surrounding the vehicle. The "ideal" condition would be a IC than can reduce the exiting air temp to the same as ambient (which is impossible to do). But the more the temperature can be reduced the better. That's why a bigger intercooler may be needed here. However it is not only size that matters, the efficiency of the IC design also matters.
Second, as mentioned there is not a lot of airflow in the X's engine bay. You did a nice job of adding a air duct to the IC, but it might need more help. Especially at slower vehicle speeds. Connecting the duct to your radiator fan (as you described) is good. Perhaps even better is to add a small fan directly on the IC.
Third, any additional insulation to separate the "hot" stuff from the "cold" stuff will greatly help. As suggested already things like ceramic coatings on the manifolds, heat shields, increased air circulation around the turbo, etc.
A couple things I've learned about this is the temperature inside the intake manifold increases when there is more "resistance" to airflow inside it and the rest of the engine (head and exhaust system). The easier it is for the air to flow into the turbo, through the IC, through the intake manifold, through the head, through the exhaust manifold, through the turbo, and through the downpipe/exhaust pipe, then there is less resistance (friction) and lower back pressure, so the temps are cooler. And the temp increases in a exponential way (multiple times greater as it rises) as pressures go up. So anything you can do to make the flows easier/smoother, the lower the charge temps will be. That might include things like the diameter of the air pipes that connect everything, the sharpness of any bends, porting of internal surfaces, bigger IC, etc.