Factual error: When Marty hits his head on the DeLorean's steering wheel, the car's horn honks. This is inaccurate to the design of real-world DeLoreans, as a DMC-12's horn button is actually located at the end of the turn signal lever rather than in the steering wheel. (01:39:27)
Suggested correction: You can't see his left hand and he could have accidentally pushed it when he hit his head. Or Dr. Bown customized the steering wheel so the horn is in it, like he customized the entire interior of the car.
I thought the point was that the car was so unreliable that when hit his head on the steering wheel, the horn went on. Makes sense to me. I own a DeLorean by the way.
Continuity mistake: When Marty arrives in 1955, he puts the DeLorean behind the sign, and walks into Hill Valley. When Marty and the 1955 Doc come back later, the DeLorean is facing the other way round to what it was at the beginning (you can tell because at the start Marty pushes the BACK of the DeLorean AWAY from the Lyon's Estates billboard, but when they come later, the FRONT is facing TOWARDS the billboard). (00:35:05 - 00:51:15)
Continuity mistake: In the scenes where Marty enters the Lyon estates, if you look close you can see a stop sign, but if you watch the next two movies the stop sign has been removed. (00:11:50)
Suggested correction: I watched the films and the stop sign is still present.
Continuity mistake: When Marty is riding his skateboard to school in the beginning, he waves to a driver and you can see his wearing a watch on his left hand. However, look at his left hand when he meets up with Jennifer, and you'll see that it's gone. (00:06:10 - 00:07:00)
Suggested correction: There's a time-lapse directly before Marty arrives at school. There was plenty of time for him to remove the watch offscreen.
Trivia: The town hall building is also seen in the Voyagers TV show.
Suggested correction: The Town Hall building is in over 100 movies and TV shows since it is a building in Courthouse Square at Universal Studios. It has also appeared in Gremlins, The Twilight Zone, To Kill a Mockingbird, Knight Rider, Leave It To Beaver, Parenthood, Saving Mr. Banks, and Psycho II, to name some of a few of the more commonly known. I don't think its common appearance makes this trivia relevant.
I'd say it makes it more relevant. Just add the multiple appearances of the building.