I parked on a single yellow line yesterday just outside a busy shopping centre. The only reason i did this was pure frustration as i couldnt get a place in the pay and display and had been driving round and round. the car park very frustrated...anyway to the point !...When i returned to my car a very miserable looking traffic attendant ( not the ones with the yellow line around their hat but the ones in grey and green uniforms ) was stood next to my car and was writing (pressumably) a ticket for me . I hastily got in my car and sped off into the distance as i was sure that i had read somewhere that if the warden / attendant doesnt put the ticket on your windscreen then the ticket is not valid ?? Anyone know if this is correct .....