In the last few shots in the movie, as the Character is leaving the airport, there is initially a departing Vickers VC10 airliner flying overhead from right to left, this changes to a close up, followed by a shot of the same airliner now flying into the distance - unfortunately this is different 4 engine Jetliner, probably a Boeing 707.
When Brown and Smith are driven out to see "Duvalierville", they are in a 1962 Buick Electra convertible. However, when they return to the hotel, the group is in a 1964 Buick Skylark convertible.
When Brown and Jones wake up in the country graveyard, it is supposed to be morning and their shadows are clear on the large gravestone right behind them where they slept, even though it is bright all around them. But as Brown moves through the graveyard, his shadow splits into multiple shadows at different angles, revealing that there are multiple lights from different angles. And in fact, before long several more realistic sun-cast shadows appear on the ground around him from taller objects, pointing in the opposite direction from the artificial lighting, showing that the sun is actually behind and above them, just past noon, and not low in front of them.