Factual error: The video games Operation Wolf and Rampage were visible in the Family Amusement Center arcade during the opening. However, this would not be possible during the movie's 1984 setting since Rampage wasn't released until 1986 and Operation Wolf wasn't released until 1987. (00:12:48)
Factual error: Trevor was driving ECTO-1 at over 60 mph. Podcast was driving the remote car and it was pulling away from ECTO-1. There is no way that the remote car could be going faster than ECTO-1, unless it was souped up, which it didn't appear to be when looking at it.
Suggested correction: There are plenty of RC cars on the market right now that anyone could buy that are capable of going 60+ MPH (the fastest can hit about 100 MPH). And if you take them apart, they don't look "souped up" at all. They just look like regular RC cars inside. Components don't have to look fancy to function fancily. You also have to account for the fact that the movie is highly fantastical, so there's no telling what kind of technology the RC car uses... for all we know, it could be nuclear-powered like the proton packs.
Factual error: Real-life Martina Franca is a town in Puglia, at the "heel of the Italian boot." The town shown in the film is the famous San Gimignano in Tuscany. And when Holly "defects" in order to go to the Hill of Tara, her departure point, as seen on Foaly's observation monitor, is the real-life location of San Gimignano. (00:35:50)
Factual error: After Maya Peters is brought into the recompression chamber because of an injury, the timer is shown counting down by hundredths of a second and skips from 1 to 0 without showing 0.99-0.01. (01:24:30)
Factual error: Joel is using a ham radio set to contact his old colony. A shot of the radio set shows it is set to "CW", which is Morse Code, but he is using voice. And the strength meter is on zero. It should be showing the signal strength. (01:24:00)