First foray into drawing vehicles

When he first started drawing, S only drew vehicles. He just loved anything with wheels. He started drawing when he just turned two 2 years old and he used to ask me to draw for him cars. After drawing a few in 2D, he started drawing on his own. The first vehicles that he drew were rectangular vehicles with wheels at the bottom. They were trucks, cars and trains. Below were his drawing when he was around 3 years 5 months.

He gave the vehicles a face, like those that he saw on Thomas and Friends and Disney Cars