ROCHESTER — On Friday the parking lots at Old Colony Regional Vocational Technical School were full: one of cars, and a few people in transit, and another with a handful of elaborately decorated cars and a throng of trick or treaters that milled around between them.

“Trunk or Treat” was a chance for students and teachers at Old Colony to showcase their creativity, for kids to show off costumes and get candy, and for the school to raise money for 21 Friends.

Though the event was free, one high schooler braved the chilly weather to stand by a table and collect money for the non-profit, which helps people with Down syndrome.

The groups that put together cars for the third iteration event had a variety of different methods for picking the themes for their cars.

One group, who chose “The Wizard of Oz” as their theme, and another who chose “Winnie the Pooh” wanted to appeal to the kids there to trick or treat. In a similar vein, one vampire bat  themed car came about because a participant’s younger sister suggested it.

One mother of National Honor Society member Zachary McMahon mentioned that her late husband was a huge “Star Wars” fan, and passed the love of the films on to his children, inspiring a “Star Wars” car.

One duo found an idea to make a McDonald’s booth on Pinterest and did it because it was affordable. Another group was inspired to do a “Jurassic Park” themed car because one of the students had the Jeep that appeared in the movie.

One mother daughter duo did a Halloween themed car, with Caitlin Frates dressing as “The Invisible Man.”

Asked why they chose the theme for the car, Frates answered: “I didn’t want to show my face.”