Continuity mistake: When Ernest picks up the Christmas tree from the freeway, he throws the Christmas tree into his taxi. It smashes the driver-side rear window. But, when he drives away, that window is still intact.
Continuity mistake: The first time we see Ernest driving the cab the passenger pats his shoulder telling him to hurry up. The passengers hand was on his shoulder when he said this but in the next shot both his hands are on his briefcase.