Getting nauseous in other people's cars is something I've often struggled with. It seems to be caused by a mix of factors like irregular movement and smells that are foreign to me. The motion of the car can mess with my brain's sense of balance, leading to feelings of nausea. Unfamiliar smells, like air fresheners or cleaning products, can also trigger this uncomfortable sensation. It's definitely an unpleasant experience, but understanding the cause can help manage it better.