I hope the tranny oil level is still correct and the engine is not overheating from a failed waterpump. Could be a dragging brake. Brake linings have an unusual hot material smell. Check underhood next time you smell it. There was a recall on engine cooing fan wiring. A slipping a/c clutch or belt is possible. I had oil dripping on the exhaust system on the passenger side of the car, it smelled when the engine got hot. It smelled different then "blue smoke" oil smell, and took 20 minutes, oddly enough.
