Continuity mistake: When Rhonda grabs a javelin and spears the Creeper through the head to save Bucky, he loosens his grip and they all back away. The javelin is left sticking out of the hole, jerking around for a bit, and then is suddenly lifted out of the roof. In the next shot of the Creeper on top of the bus the javelin is still in the hole, and then he lifts it out slowly.
Continuity mistake: Through most of the movie when the Creeper smiles, you can see his yellow teeth. But at the end when he is attacking Double D he has white teeth.
Answer: The car explodes a while after it crashed, too fast for Izzy to get away.