Not sure what's up with the temp gauge. I had a long wait, and the engine temp on the gauge started climbing. I figured the temp would drop when I started moving. Then I hit some red lights. The temp climbed to the red. So, I pulled into a vacant lot and parked. I left the engine off, but every few minuted, I'd turn the key to check the temp. The gauge would move to about halfway, then go up and down, eventually getting into the red. This went on for 12 or so minutes. The ECU showed the temp was OK, while the engine had bern running, and the temp probably is OK. I did open the decklid, to let the hot air out. The dnhine did cool off, down to only moving the needle up about 1/4th of the way. After those 12 minutes, I closed the decklid, and drove home. The temp never got above halfway.
This is an ongoing issue.