These were fun.
I found this great idea on Artsonia here for a Kindergarten lesson last week. On an 12 x 18 piece of heavyweight white paper, students used Sharpie to draw a horizon line and then buildings in the background. (Some of them got very creative with their building shapes!) Then they drew some road lines (although most of these ended up being covered-up by their trucks). Students each got a small stack of coloured rectangles (I think these were 2 x 3) and arranged them in the rainbow order. I gave a brown square and rectangle for the front of the truck and some small black squares for the wheels, which they cut into circles. Once arranging their order, they glued on their trucks. Finally, some students decided to add more details (such as ice cream cones, people, planes etc.).