Dizziness in a car is a symptom of motion sickness, a collective term for motion sickness, seasickness, airsickness and disorders due to various causes of swaying, bumps, spinning and accelerated motion.
The main symptoms are dizziness, headache, nausea, vomiting and, in severe cases, even collapse and shock, accompanied by pallor, cold sweats, tachycardia or bradycardia, decreased blood pressure, nystagmus and loss of balance.