So, as a follow up I drained the radiator and replaced the thermostat this morning and it solved my issue. Now, I didn't think it was going to because when I looked at the coolant, it appeared to be brand new! Clear, pink and not funny looking. When I got the thermostat out, I also was surprised to see that it also looked NEW!! After cleaning the mating surfaces and getting everything back together I was worried that it wasn't going to make any difference... I fired it up with the heater on high, and let it run for 20-25 minutes and then took it for a spin for another 20-25 minutes and I never heard the fans kick on, which was a great relief!! I did also notice that the fans were actually running, but at such a low speed that I couldn't hear them, so I assume that I had never heard them kick on medium/high speed before and they must have always been running as when they should have but I never noticed. I've included pictures of the old thermostat and coolant after I drained it. I'm amazed at how clean the inside of the radiator and thermostat housing are for a car that has 299,000 miles!!!