Oder from dash vents
 

Car is 1992 300TE

Oder occurred suddenly. Hard to describe, wife said she thought something was burning. It made her eyes water.

A/C and heat work fine.

Not sure what it is or what is causing it. Do not think it's coolant or R134a, but what else could it be?

me too
 

I have a similar issue. Mine smells like something died in there. Did you get you problem resolved.

Check to see if your AC condensate drain is clogged.
If it is you'll get a musty, moldy, critter dying smell......

Does it smell like plastic burning?

It could be the Wiper motor. Mine failed and blew acrid smoke into the cabin while on I-35. (1995 E20 Wagon)