I would talk to the person. They're probably parking in front of their home, right? I would knock on their door and explain how this is a real problem for you and others in your neighborhood.

I had a neighbor who turned their house into an Airbnb, and sometimes their guests would park blocking the sidewalk. I would draw a picture of people with walkers, baby carriages, dogs, wheelchairs, etc. trying to get around their vehicle, and put it under their windshield wiper, asking them to please not block the sidewalk. They would always keep their car off the sidewalk from that point on.

Fortunately the city has cracked down on illegal Airbnbs, so it's not a problem for me anymore. But a personal approach would be even more appropriate when dealing with a neighbor. Anyway, it couldn't hurt to try.