Burning scent

I have a 2000 Toyota Yaris, about 32000 miles and I have had problems with rats chewing the wires in the engine. The dealers suggested I put rat food on the engine. About two weeks ago it got wet and shortly thereafter there has been a burning plastic or electric smell in the car, I don't know if they are related. I took it in to the dealer and they said it was the rat food. I cleaned the rat food off the engine, but I still smell the odor, it is not as bad as it was, but it is still there. Sometimes it smells as if wires are burning, however, after I park the car I don't smell it in the engine or under the car. Could the rat food have gotten somewhere else and is still burning, or is there something else I should be looking at. This is causing me alot of distress.

Have you tried looking for the source of the burning smell while the car is still running? It could either be some leftover residue from the rat poison or a rodent has possibly chewed on some wires.

I am usually in the middle of trafic when I smell it. I have checked the engine and under the car for the smell when I turn the car off, but I haven't been able to track it down.

does this happen when you have the air re-circulating or drawn from exterior or both?
pongy smells could also be from a dirty air filter in the aircon.
30,000 miles sounds about right for this as well.

Actually I get a burning scent, but slightly different scent from re-circulating and drawn from exterior. I let another mechanic look at it, he says its the converter, but I will hold my breath. I have had people tell me different things before and it wasn't.