Jersey Police are looking for two people who allegedly threw glass bottles that were on fire in the St Saviour's Parish Hall car park on Monday 2 May.
One hit the floor and the other hit a parish vehicle just after 9pm.
Both burnt out and no one was harmed or injured.
Officers say the two suspects ran back up St Saviour's Hill towards Five Oaks.
Cars were driving past at the time and officers want to speak to those drivers.
Anyone with information is asked to call the police on 612612 or Crimestoppers anonymously on 0800 555 111.

Jersey Airport departures lounge set for 'big' transformation
Minister: Hopes of recouping up to £3m of Blue Islands' debt
Woman jailed for cocaine hidden in chocolate wrappers
Channel Island musicians record Christmas song at Abbey Road
Wind farm progress paused over export uncertainty
Direct flights from Jersey to Southend revived
Electricity prices to rise by 2.5%
Jersey's community comes together to reimagine the Occupation Tapestry