A Perth man who had his car broken into last week has sent a very unusual message to the thief - "thank you!"

On Saturday, Tom Drury's uncle notified him the backdoor of his 1994 Mazda had not been locked properly when it had been parked on their Morley front lawn.

Upon investigating, Mr Drury found his car been broken into, and the thief had removed the stereo from the front dock.

While many people would be frustrated and upset by a missing sound system, Mr Drury said the news wasn't at all bad.