XJ runs too cold

Hello all,
So I decided to build a cold air intake and deleted the factory air filter box. Created a lot of air flow in engine bay. XJ ran a little cooler through the summer...great! No vapor lock or overheat issues. Wonderful.
Now it's Fall and the temps have dropped down in the 30's, Jeep doesn't get to a good operating temp even after 24 miles or sitting for 15 minutes at idle. Luke warm air from heater.
All systems are in good condition and operating like they should. The problem is there is just too much air flowing over engine to allow it to reach operating temps.
So my question is, does anyone know of a product that's easy to install/remove to block air flow over radiator that doesn't look like a crappy piece of cardboard stuffed in front of radiator (which I've done). Would like something that looks better and serves same purpose.