I brought out paint (Crayola Washables), large brushes, a bowl that we filled with soapy water, and a sponge. My idea was to paint her Little Tykes car, and then wash the paint off. She didn't like that idea. Instead she wanted to wash the car, then paint it and let it dry. O...kay.
We made the water overly soapy, because it's just more fun that way, and as she scrubbed all over the car, she was so deep in concentration. I thought this would be fun but she looked so serious! Afterwards, she got to use the hose to rinse off the soap (and, of course, turn the hose on herself as well).
Then she went for the paint and focused on adding color. It still sits in our yard, splashed with pink and purple hue now, in addition to the regular red and yellow. I'm hoping next week she'll be interested in washing all that paint off!