If you write "Clean me" or "Wash me" on someone else's filthy vehicle this winter, you might be charged with criminal damage.
Winter makes it more difficult to maintain your car clear of muck, whether it's sludge from melting snow and ice or mud from incessant rain.
If you used enough pressure when daubing a message, you might even leave a 'ghost' of a word on the paint that remains evident long after the owner washes the vehicle.
"Overall, your polite 'banter' might backfire spectacularly if the vehicle's owner chooses to report the incident to authorities."
If officers do interfere, they may drag you before a judge to recoup the cost of repairs.
If the "criminal act of vandalism" is less than £5,000, a fine of up to £2,500 may be imposed.