From Homestar Runner Wiki
Although Free Country, USA doesn't appear to have sufficient roads nor any of the necessary infrastructure to support cars, various characters have talked about driving and purchasing cars. A few actual cars have also been spotted, although they generally appear to be non-functional.
- Homestar apparently owns an auto, which he checks under in search of his hat in both Where My Hat Is At? and the toon remake.
- The Gremlin is a car that made its debut in Homestarloween Party and has been used in various toons since then.
- The Interview — Homestar claims that he drove to Marshmallow's Last Stand. Strong Bad then says to Homestar that he doesn't own a car, to which Homestar replies "Yeah. You're probably right."
- Bubs' Character Video — Bubs mentions cars as one of the many things that he can fix.
- Email credit card — One of the things on sale at "the-coolest-stuff-ever.com" is a golden limousine, priced at $900,000.
- Nighttime Driving Type Game — This game involves different cars.
- Email 12:00 — During the VCR Easter egg, one of the many VHS tapes is labeled "car commercials".
- Email helium — Strong Bad's intro involves him saying the word "email" like a car going through various gear shifts.
- Email vacation — Strong Bad visits "Two Cars Tennessee".
- Email caffeine — As part of Strong Bad's project of "The Effects of Gasoline on Fire", Strong Bad provides drawings of cars.
- Email car — Strong Bad claims not to own a car.
- Teen Girl Squad Issue 9 — Learner's Permit Girl drives a car over Cheerleader, and later gives Strong Bad a ride to Babbage's.
- Fall Float Parade — The two Homsars are driving small red toy cars.
- Email pop-up — The Cheat wins a car.
- Email the movies — Strong Bad watches a movie called "Karate Car".
- Email what I want — Strong Bad wants a chainsaw car for Decemberween.
- Homestar Ruiner — Giving a Teen Girl Squad girl car keys prompts her to announce that her real dad bought her a car, but gave it to his girlfriend — except for What's Her Face, who still has hers, but it explodes when she attempts to drive it.
- Decomposing Pumpkins — Brainkrieg sing about driving around in their mom's car looking for rotting pumpkins.
 Hybrid Cars
- Email secret identity — Marzipan reads an issue of Scarfgirl magazine, which mentions "Hybrid Cars" on its cover.
- Marzipan's Answering Machine Version 13.2 — In a prank call, Strong Bad tells Marzipan that her subscription to "Soy... Bread... Tofu... Hybrid... Cars... Magazine" is about to erupt.
- Kid Speedy — When you beat the game as Homestar Runner, Marzipan says "NOW WE HAVE ENOUGH FOR A HYBRID CAR, OR MAYBE...", but it shows Homestar and Marzipan in the hybrid car before Marzipan can finish her sentence.
- Email environment — Strong Bad tries to drop a "65 mile-per-gallon hybrid piano" on Strong Sad and Marzipan.