2002 SAAB 9-5 issues?

I have a situation with my 2002 SAAB 9-5 that I am not exactly sure how to handle. I was driving today, and out of nowhere all the display lights in the gauge cluster turned on for 5 seconds then back off. I did not notice any mechanical or performance difference. When I got to my destination, I noticed an odd smell (like rotten eggs) coming from my car. I popped the hood, and a significant amount of heat was coming off of the engine (more than normal). I checked the temp gauge, and is was where it usually is during normal running conditions. I proceeded to go to the exhaust to see if the smell was there, and noticed that the exhaust, while supposed to be hot, was REALLY HOT. Also the fans kept running continuously. Once I shut the car off I went to check the oil, and steam/smoke was coming out of the filler cap. Any thoughts? It seemed to be running fine goin down the road.