The police are asking people to report any suspicious looking vehicles that they see driving in the early hours of the morning.
It follows the theft of four 4×4 vehicles across the county overnight between 10.30pm on Sunday and 2am on Monday.
The incidents took place in Gloucester, Cotswolds and Tewkesbury.
It was reported that a dark blue vehicle – possibly a BMW or Mercedes – was seen in the areas at the time of the thefts.
Detective Superintendent Steve Bean said: “It is unlikely that any vehicle with multiple occupants that is driving in the small hours of the morning will be doing so for essential travel or because they are key workers.
“I would ask that anybody who has seen a vehicle with multiple occupants who they do not recognise, driving in their area overnight, reports it to us.”