Gloucestershire Police are asking drivers to be extra vigilant when leaving their cars parked at home.
It follows the thefts of two Audis in the past week.
The first was reported stolen on Thursday October 30 after thieves broke in to a nearby property in Innsworth, Gloucester and took the keys. The Audi A7 has since been recovered.
The second was reported stolen yesterday outside a property in Up Hatherley, Cheltenham. Again the keys were taken during a break in at the property. Description is: Black Audi A5 convertible, registration VA61 BWN.
A police spokesman said: "We are not sure at this stage if Audis are being targeted but would ask all motorists to be extra vigilant when leaving their cars outside their homes.
"Make sure they are locked and parked in a well-lit area if possible. Also make sure you hide your keys inside your home, don't leave them anywhere obvious."
In reference to the first Audi stolen, Gloucestershire Police would like to thank a member of the public for helping them recover this vehicle.
The person noticed the car today, parked in Fieldcourt Gardens, Quedgeley.
Police would like to hear from anyone who knows more about how the car got there by calling 101, please quote incident no. 44 of 04/11/14.
If anyone can help with the Audi stolen in Up Hatherley, again call Gloucestershire Constabulary on 101 - quoting incident no. 442 of 03/11/14.
This Audi A5 TFSI convertible was stolen in the last 72 HRS from an address in Hatherley. Have you seen it? Log 442. pic.twitter.com/OhFQm9tjjo
— Glos Road Police (@GlosRoadPol) November 3, 2014