The Hairy Scare of the Devil Bear - S1-E8
Character mistake: Velma says bears only have four claws. Wrong, they really do have five claws.
Route 7-11 - S1-E12
Character mistake: In this episode, they constantly refer to the semi as an eighteen wheeler. The tractor would have tandem (two) rear axles with dual tires. This one has only one rear axle on the tractor. Added up, the rig only has fourteen wheels.