The attacks on vehicles took place in Norton, near Malton, during the early hours of Saturday.
North Yorkshire Police said the vehicles parked in Scarborough Road were damaged some time between midnight and 6am that day.
A spokesman today said: "We are requesting the public’s assistance to help establish the full circumstances surrounding the incident.
In particular, we are appealing for information about if anyone was seen in the area between the times of midnight and 6am on Saturday."
Anyone with information is asked to email [email protected] or call North Yorkshire Police on 101, select option 2, and ask for Louise Neville-Beck.
Information can also be passed on anonymously via Crimestoppers on 0800 555 111.
Please quote the North Yorkshire Police reference number 12180015195.