In the sequel, Fender called the police, but there was no one there to answer. Instead, they had a recording that said "Leave a message.". What kind of police station doesn't have anyone to answer the phone?
In reality, everything Diesel had done was all sorts of illegal. She would be spending several years, if not the rest of her life, in jail for attempted and successful murder, deliberately poisoning her customers, and creating debts for her employee and customers. Why she was only arrested for driving with a revoked licence and having an expired registration is a mystery.
Sparky, our Designated Hero. He always complains about his dad trying to ruin his life and is constantly rebelling, trying to prove that he can do things on his own while failing spectacularly. He also doesn't put things together that Diesel is trying to destroy his life and potentially kill him.
Speedy, moreso. She speaks in a loud, high-pitched voice and is very stupid, if not oblivious, to certain aspects of the film.
Pretty much anyone that isn't Fender, Diesel, (maybe) Norbert, or Julia, the tire pump who speaks a grand total of two words in the film.
Strangled by the Red String: Zipper and Sparky's relationship. Zipper automatically develops a crush on Sparky during their first encounter and instantly wonders to himself who Dash is. He spends the second movie trying to ask her out and proposes to her in the end. The third movie gives them their own side-story about their marriage.
Surprisingly Improved Sequel: Zig-Zagged. While everything looks and sounds better in the sequels, and Speedy is less annoying than before, the stories are debatably even worse than the original's, mostly due to being longer and full of Padding.
What an Idiot!: In the climax of the first film, Speedy doesn't realize that Diesel is trying to kill her and Sparky. She even gets mad at Sparky for trying to make her understand what's going on by saying that Diesel is "being nice to them". She's already considered a Scrappy (see above), but this just makes her character more annoying.