On my way home from work, I heard a beep coming from my dash, a single short beep. All my gauges look fine, no warning lights, car runs fine, but I still heard the beep.

What could it be? Or was I hearing things?

...if you have the trip computer, you could have inadvertently set the speed sensor to warn you when you exceeded a certain MPH. It took me a while to figure that one out. The manual will tell you how to disable that function if it is set.

A beep accompanies the fuel warning light.

Lights on? If so - All doors shut tight? Trunk shut tight?