The thieves are understood to be gaining access to the vehicles' remote unlocking fobs through household or business burglaries.

While the theft of modern vehicles has been much reduced through the phase-out of conventional keys and the introduction of remote keb fobs with inbuilt "rolling" codes, leaving garages or businesses insecure and the fobs easily found has given thieves the easiest of opportunities.

One of the cars, a high performance all-wheel-drive Audi TT RS stolen from a Mitchell business on December 5, was found burnt out around 10 hours later on Isabella Drive, Monash.

The two others, a Skoda Kodiak RS and a BMW 440i coupe, are still unrecovered.

The Skoda SUV was stolen from a residence in Harrison on November 25, while the late model BMW was stolen from an O'Connor garage in the early hours on December 3.

It is understood the thieves have used a bright orange Citroen Cactus, also suspected to be stolen, to "scout" for their targets.

ACT police say that "people may believe that because of their new car's safety features it is less of a target for thieves".

"However, thieves are opportunistic and will look for opportunities to break into your house, like through an open garage or door, to steal your keys to unlock your car," acting Detective Inspector Emily McCallum said.

"Our simple message is: lock and hide to protect your ride.

"That is, ensure the doors, windows and the boot of your vehicle are locked, even when you are at home.

"You should also not leave valuables such as wallets, handbags, phones, tablets etc. in your vehicle, even if it's locked.

"When you're at home always leave your keys in a secure place - some people leave them in a bowl by the front door etc., which can be easily located by opportunistic thieves."

Investigations by police into all three incidents are ongoing, including any potential links between the incidents.

Anyone who sees these stolen vehicles or may have information which can assist police should phone Crime Stoppers on 1800 333 000.