Burning smell for about 30 seconds

While driving my toyota corolla 2006, I smelled a burning smell and saw a small amount of smoke for about 30 seconds coming out right by the windshield wiper , this happened twice within an hour period.
What could this be?

A very slow oil leak that’s dripping on something hot can do this. Look closely with a flashlight for any signs of that.

Most cars have a lot of wiring that runs across the top of the firewall and heather air inlet tray. Examine that, checking for burnt spots.

The fact that it repeated would lead me to believe it’s not wiring, but a fluid dripping on something hot, like an exhaust pipe.

I had a radiator spring a leak on my Corolla one time and something similar to that happened. I was in San Francisco and thought it was a fog bank, but the fog was from my Corolla’s radiator instead. So the “smoke” coming from under the hood and up past the windshield might be coolant steam. Hot coolant does have a distinct odor. I wouldn’t describe it as a “burning smell”, but it is an unusual acrid aroma and I could see somebody thinking it as a burning smell. It’s a good idea a to have your coolant level checked asap b/c if you do have a leak, it could cause the engine to overheat and major damage can result. It has to be checked at the radiator, not just the plastic bottle. This is something any inde shop can do. Don’t try it yourself unless you have the requires skills b/c hot coolant spewing out the radiator cap is dangerous.