Motorists are being urged to be on their guard after a series of raids on cars in Doncaster.
The warning comes after a 30-year-old man was arrested in connection with thefts from vehicles in Sprotbrough this week.
In the early hours of Tuesday, a member of the public told police they had seen a group of men behaving suspiciously in Crompton Avenue.
It was reported that the men were trying car door handles in the area.
Officers said the man was arrested on suspicion of theft before being bailed by officers pending further enquiries.
Two satellite navigation systems were recovered.
Officers are still trying to trace the owner of one of the systems, who has not yet reported the device as being missing.
A South Yorkshire Police spokesman said: “If you’re a motorist in the local area, check your vehicles and glove compartments and if your system is missing, please call Doncaster CID.”
Anyone with information about the remaining stolen sat-nav should call 101 quoting incident number 99 of August 9.
Likewise, anyone who witnessed suspicious activity in the Crompton Avenue area earlier this week, and wishes to report any concerns, should call the force on 101 quoting the same incident number above.