Corrected entry: When Sgt Wilson puts the invoice for the gun on the desk, he moves the lamp. It is seen that it is not connected as we see two bare wires.
Corrected entry: Dick Dastardly is seemingly unable to win, yet always manages to get in front of all the other racers several times a race. He gets in front to boobytrap the race course, which usually backfires, making him further behind. He then ends up in front again somehow. Since he manages to advance through sections of the racecourse so fast and so many times, it makes no sense to why he can't simply win the race fair and square when he obviously must have the skills/car to do so.
Correction: Not really a plot hole. Remember that Dastardly and Muttley are both phenomenally stupid and villainous so it is within their character not to realize that they could win the race honestly.
Corrected entry: Mayberry and the Mexican town of Puerto Bello become Sister Cities as part of a State Department program to foster friendship between nations. Everybody in Mayberry continually mispronounces the Mexican town's name as "Porto Bello."
Correction: Hardly a mistake that small town Americans can't pronounce Spanish names properly, even if they are friendly.
Correction: Since the lamp isn't on this simply demonstrates how tatty their equipment is.