A black Mercedes was used as a getaway car after thieves broke into a home and stole the keys.
The incident occurred between Tuesday (November 1) and Friday (November 4) at a property in Station Road, Mursley.
The offender is believed to have gained entry to the property while it was unoccupied.
A set of car keys were stolen from the house and subsequently a black Mercedes was taken from the driveway. The car was driven towards Bletchley.
Investigating Officer PC Lauren Suffling of Aylesbury Local CID said: “I am encouraging anyone who has seen anyone acting suspiciously or any suspicious vehicles around the area to get in touch by calling the Thames Valley Police non-emergency number 101.
If you do not want to speak directly to the police you can contact the independent charity Crimestoppers anonymously on 0800 555 111.
No personal details are taken, information is not traced or recorded and you will not go to court.