Were they acting out of character though? Because from the time they were in the car until the scene pictured, they seemed pretty consistent to me. You could make the argument they were influenced all the way back at the beginning of the movie, but I always was pretty horrified (exaggeration, but general feeling) and on chihiro’s side as soon as the car stopped. The desire of her parents to walk through the tunnel and continue on always seemed weird. I like planned adventures, not to have an impromptu stop while moving. We can have fun and explore once the absolutely critical task is done, goddamnit! I will not succumb in fiction to what I do in real life!