The car was put in place Tuesday morning, and students said they hope it will influence the decisions made prom night about drinking and driving.
"Underage drinking has been a problem in the past, and that is why we are pushing the program so hard this year," CHHS senior Julie Wheetley said.
Wheetley, who is president of Students Against Drunk Driving, said the organization has planned several activities to warn students of the dangers of underage drunken driving.
SADD is working with school officials to take steps to curb underage drinking and driving by arranging demonstrations and possibly giving breathalyzer tests at this year's prom.
This will be the first year CHHS has considered giving breathalyzer tests at the prom, but the idea comes from another local high school.
Chapel Hill Principal Mary Ann Hardebeck said East Chapel Hill High School had the tests last year at its prom, and they proved to be very effective among the students.
"We want to promote the safest possible end-of-year activities and show kids that they can have a good time without alcohol," she said.
CHHS senior Elizabeth Eubanks said she thinks breathalyzer tests at prom would be a good idea for students.
"I know some kids are upset and will try to find ways to get out of the tests, but they will get over it," she said. "I think students should wait and drink at after-parties if they are going to drink.