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.
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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.'
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the rest, including many examples of his work, at DM link above

Mr Burden's website