Toy Story 4Goofs
Bonnie's dad is guilty of dangerous driving. Unaware that living toys are affecting the RV, to him it's just responding erratically to the controls. Despite that dangerous situation, he attempts to drive forward instead of stopping the vehicle in neutral with his foot hard down on the brake pedal, and the ignition switched off.
Errors in geography
At the end of Toy Story 3 (2010), Andy's house only has one driveway. During the flash back in the beginning of Toy Story 4, there are two driveways - one leading up to the garage and now one on the left side of the house.
While there were indeed talking dolls with a voice box that is easy to remove if not user-serviceable, given Gabby's age as presumably an early-model Gabby Gabby doll, it would be in reality extremely difficult to remove and reinstall her voice box. Not to mention excruciating for both Gabby and Woody.
Incorrectly regarded as goofs
Bo Peep's timeline is full of mistakes. She was donated nine years before the film. When she meets Woody she says she's been "lost" for seven years. Based on various comments, in that two-year time span she was given to a little girl who grew up to not need her and spent years in the antiques store before getting bored enough to go on her own. Bo is part of a bedside lamp. It is easily conceivable that she was bought for a little girl who was afraid of the dark but had outgrown the fear two years later. The seven years after that include her time in the antiques store, because she says that she has been out on her own (i.e. without a kid) for seven years, not that she has been living the life she does now (i.e. without waiting for or even wanting a kid) for seven years.