All interior ignition lights on? tank empty, oil low etc...
 

I started the car up this morning and all of the interior dash lights are on....

check engine, oil low, gas tank empty, bad light bulb, fog lights etc....

They are all stuck on.

Any ideas? It just suddenly happened this morning.

Alternator not charging.

ps2cho, the voltage regulator brushes are probably worn down to the point that the alternator isn't recharging the battery properly. Remove the 2 screws that secure the voltage regulator to the back of the alternator and check the brushes. Removing/replacing the voltage regulator is an easy DIY job.

This could have something to do with your post below re.: Misfire. ;)

A 580 watt audio system would use 50-60 amps when operated in "head-banger' mode.

I think the car has a 70 amp alternator if my memory is correct.

Also check your ground wires
 

This sounds to me like a ground issue.

I had a similar issue on my BMW. I fixed the loose ground and the problem went away.

On my 300SD the gound is a brown wire attached to a post under the instrument cluster. Try pulling the clustger and checking for any loose brown wires. I would also check the ground strap for the body, engine and the negative post on the battery.