Aurora Engine Dies/Sporatic Electrical Issues

We have a 1997 Oldmoblile Aurora with about 121,000 miles. About Five months ago while driving to California in heavy traffic(stop and go) the car died. We pulled the car over and let it rest for a while, believing that we had probably drained the battery over night and were using to many electrical systems(AC, radio, electric cooler, and IPOD). We stopped the car for awhile and recharged the battery. We recently had the car in at a dealer to have a couple items fixed, only electrical was the driver seat switch was replaced. Two days after getting the car back from the dealer we noticed the lights flickering on and off for no reason. Then it stopped. Then about 2 weeks later the door locks started locking and unlocking randomly. Then it stopped. Now today, the car died at least 5 times while driving under 20 mph. We could place the car in neutral and then get the car restarted.

I believe there is something majorly wrong, but can't put my finger on it. Is it a computer or wiring harness going out or just a few sensors?

Need some help and advice.