The blue Volkswagen Beetle had been parked on Valnord Road, St Peter Port, when the substance was left on the handles sometime between 16:30 on Sunday 3 May and 07:00 the following morning.
Guernsey Police are investigating and any witnesses should contact PC 100 Sam Simon on 725111 or Crimestoppers anonymously on 0800 555 111.
Pictured top: File image.
