Two vehicles taken from properties in the North East were recovered overnight.
A black Ford Focus reported missing from Fraserburgh and a yellow Citroen DS3 from New Deer were both recovered in the Ellon area.
Enquiries are ongoing and anyone with information should contact Police on 101 or Crimestoppers on 0800 555111 if you would prefer to remain anonymous.
Officers also received reports of suspicious activity overnight in the Oldmeldrum, Tarves and Ellon areas.
Repeated appeals have been issued in recent months urging people to ensure their properties, garages and vehicles are locked and secure at all times, and that valuables are kept out of sight.
Unfortunately in many cases the perpetrators have succeeded when house and vehicle doors have been left insecure.
Detective Inspector Stuart McAdam said: "The overriding worry for us is that these opportunistic thieves do not seem to care who they target, what they take and who they might hurt in the process.
"This is nothing more than a thrill for them - however it's a thrill that can cause their victims a great deal of upset and expense. It also goes without saying that vehicles in the wrong hands could have fatal consequences if the worst was to happen.
"It's also becoming apparent that these people are willing to return to communities which they have targeted before and where they have been successful. We're lucky to live in a region with relatively low crime levels, but I would urge the public to not become complacent when it comes to their security.
"In the majority of cases perpetrators are simply trying house and car doors until they find one unlocked and in many cases vehicles which have been left unattended and insecure have been taken. It is worth bearing in mind that failing to lock your doors may negate any insurance claim, as some insurers may not pay out in such circumstances.
"I can assure the public that bringing these people to court is at the forefront of our policing priority under Operation Magpie and we will continue to use all available resources and tactics available to us to detect those responsible. But we need the public's help to ensure they don't stand a chance in the first place.
"In the majority of cases there is one very simple solution and that's to lock up, even if you are at home. I would urge you to never leave items of value on display where someone looking in can see them, and also to not leave your car keys near your front door."
He added: "I would like to thank the public who have alerted us to suspicious activity in their areas which will be crucial to our enquiries. I would also encourage people to continue to contact Police if they see any unusual people or activity where they live, and to let us know as soon as possible."