Continuity mistake: When Jacob and Beth are talking about not being in a relationship, Beth's hair is blowing wildly in one shot but still in the next. (00:07:30)
Continuity mistake: At the very start, the guy who is giving the instructions about the college is on the path. Next shot of his feet he is on the grass. (00:01:10)
Continuity mistake: The morning after Beth and Josh have sex, Barry is playing on the acoustic guitar. Between shots it is either on his lap or on the stand. There is not enough time to put it on the stand between shots. (00:19:25)
Continuity mistake: When we first see Josh phone Tiffany, the way he hold the phone changes instantly. Note the little finger. (00:05:00)
Continuity mistake: When Beth asks about Tiffany, her hands are on Josh's shoulder. Camera cuts and they are on his chest. (00:15:50)
Continuity mistake: In the first scene of the movie where you see a bird view of the city you can see the filming helicopter on the bottom right corner of the screen.
Continuity mistake: When the guys arrive at the University of Austin, Kyle has a cigarette behind his right ear as they get out of the minibus and as they start their walk. The cigarette has disappeared in the next shot (when Kyle trips over himself).
Continuity mistake: During one of the driving scenes along a motorway, they are driving up the right hand side of the motorway. On the other side, traffic is coming towards the camera (as it should) but there is a broken down vehicle that for some reason is facing the wrong way, as if someone reversed down the motorway and broke down.
Continuity mistake: The diner they have breakfast at is the Gwinnett Diner (located Northeast of Atlanta), this can clearly be seen on all the coffee mugs in the kitchen. Many of the signs along the highways were either blurred or digitally altered to go along with the story.
Answer: I found what appears to be a full transcript at http://www.tvdance.com/movie-scripts/roadtrip/ although it annoyingly lacks labels on who is speaking each line.
DavidK93