The hood of my SUV is so dirty I'd like Mr Burden to create Picasso's "Guernica" atop it. (Or maybe Edvard Munch's "The Scream.")

It beats 'clean me': Artist uses dirty vans as canvas to create amazing portraits of the stars (Daily Mail)
Passersby often use it as a chance to make a (now cliched) joke about its filthy state.

But one amateur artist sees far more potential whenever he comes across a van covered in dirt.

Instead of just scribbling 'clean me' into the grime, bus driver Robert Burden sketches amazing portraits of music legends, film stars and even landscapes.
Bus driver Rob, 39, said: 'As soon as I see a dirty van or car, I just have to go for it and start drawing. Itís like an impulse.

'A van covered in filth is a canvas to me. I like turning something no one wants into art.'
the rest, including many examples of his work, at DM link above

Mr Burden's website