Criminal damage was caused to a silver Suzuki SX4 saloon while it was parked next to the speed humps on Francis Lane, Saundersfoot, sometime between 2 pm on Friday and 11 am the following morning.
Police say the damage is consistent with the rear of the vehicle having come into contact with acid or other corrosive liquid, causing the paint to bubble and peel away.
Anyone with information is asked to contact PC378 Lynsey Williams at Tenby Police Station on 0845 330 2000.