"Today's first lesson is, opening the door!"
Yuzukar was Goku's driving instructor, though he could barely open the car door by himself. His name may be a pun, much like other characters in the series, on "used car" or "Yuzu kar" given his age and fragility. One can easily see the juxtaposition between him and Goku.
As Goku's instructor, Yuzukar became frightened out of his mind in general when Goku was driving. Due to Goku being unnaturally strong compared to an average Human, while turning the wheel he accidentally ripped it off completely. Soon, Yuzukar's fright turned to terror as they started careening out of control. When the car finally came to a stop, he told Goku that it would take one hundred years to get his driver's license. But, when he gave Goku a second chance to get his license (by some miracle or just senility), Goku and Piccolo saved a school bus full of children. Basically, when he witnessed the power of Goku and Piccolo when saving the school bus while it was flying through the air, he was very moved. He told them that they did not need the licenses because they did not need them with that kind of power. Needlessly to say neither Goku or Piccolo received their licenses at this time, much to Chi-Chi's overwhelming disappointment.
Goku eventually gets his license later on in the series and is shown driving a car. One scene to reference when he was driving was during the Cell Games Saga. When Cell is about to be attacked by the Earth's military, Goku, Gohan and Chi-Chi can be seen in the car while listening to the radio about the attack. The attack inevitably failed to the horror to Goku and his family when they were in the car.