I am so sorry for you having had your car stolen. I had an Astra GTE stolen a few years ago and although it was alarmed and immobilsed, it didnt stop the thieves, as it was taken away on a breakdown lorry as I was to learn a couple of days later. I had spent about three hours earlier the same day washing and polishing it and it disappeared in a very shiny condition. Unlike you, when I phoned the police they were at my house within ten minutes.
They rang four days later to say that it was found in Edinburgh still in a clean condition apart from the filler cap, which had been removed and a plastic one in its place. They were suspicious when they saw someone taking the wheels off then realised from the number that it had been reported stolen. I soon sold it as I didnt feel the same about it afterwards.
Hope you are as lucky as I was Rhys and get it back, because if it was stolen to order as the police thought mine was, due to the clean condition it was in when found, you could be lucky.
It is a horrible feeling when you go to your car and it isnt there!