Christmas present

I'm making a scrapbook/canvas for my boyfriend, Kevin. He's really into offroading. That's a picture of him in the middle. I'm planning on making paper "trees" to put on the ones in the picture, making "mud" of brown and black paint to put on the license plate and the rubber "tire" under the truck in the corner.
Anyone got ideas for the other top corner? Or should I leave it as it is?