I parked my car in the garage and heard fairly loud buzzing noise after engine shut off. It was coming from front and I would guess inside the engine bay close to front left wheel. I didn't open the hood to investigate further.

The buzzing stopped after about a minute.

Is this something I should be concerned? Any idea what it is?

 

Open the hood and find out what is making the noise.

Impossible without knowing what it is?
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I was hoping someone knew what might continue to run after shutoff. That might give me some lead to go by.

Buzz is hard to locate by hearing alone so it helps to narrow down the areas of probable cause.

 

You could have a chafed harness so anything might be making the noise. Listen, if need be using a suitable tool to assist. If unable, try a mechanic as they're very used to noises.