The first car blaze was in Eastwood, Rotherham at around 7.50pm on Saturday.
Arsonists struck again in Denaby Main at 10pm.
Another car was set alight in Dalton at 12.25am on Sunday.
Firefighters were then sent out to a car fire in Junction Road in Stainforth at 12.30am.
Crews from the Elm Lane fire station went to a car blaze in Grange Way, Thorpe Hesley, that they were called to at approximately 6.30am on Sunday.