Police are warning young people who they believe are damaging cars in the Pembroke Dock area that they are risking getting a criminal record.
There has recently been an increase in the number of vehicles being damaged in the area and police believe young people are responsible.
Section Inspector Gareth Thomas said: "Young people may not realise that damaging someone's vehicle is criminal damage.
"This offence can result in three months imprisonment or a fine and if the damage caused is over £5,000 the penalties increase.
"When convicted, this means they then have a criminal record for life which can affect their future, in particular their employment opportunities. "We are urging parents to speak to their young people about the potential implications of their actions and warn young people that we have increased our patrols and if this behaviour continues, it's only a matter of time before they are caught."
Police are also urging the young people to think about the cost and inconvenience they are causing to others - a car wing mirror can cost around £100 to replace.
Anyone with information about damage to vehicles should call Pembroke Dock police station on 0845 330 2000.