I don’t believe that was the same group, but I’m fairly certain that protest just involved leaving a note on the windshield and using a lentil to deflate the tires. Their notes did touch in the environmental impact of SUVs, but from what I recall the notes focused on the negative impacts that SUVs have in cities. Such as the skyrocketing number of pedestrian deaths we are seeing.
Also plants will help cool and reduce humidity in an area. They also make a neighborhood feel more inviting.