A car window was smashed and a flare was thrown inside the vehicle in Shepparton.
Police said the white Holden Commodore was parked in a driveway in Runge St when the incident occurred between 11pm on Wednesday, February 7, and 7am on Thursday, February 8.
Shepparton Crime Investigation Unit Detective Senior Constable Andrew Costello said while the car did not catch fire, there was significant damage to the inside of it.
Det Sen Constable Costello said while it appeared to be a targeted attack, the motive was unclear.
Anyone with any information or who saw anything should phone Shepparton Crime Investigation Unit on 5820 5777 or Crime Stoppers on 1800 333 000 or online at crimestoppersvic.com.au