The b@stards! Unlucky mate, seems like they must have been bored or they were total amateur thieves, an alarm would have definitely scared them away. I remember when my old mk2 was vandalised, side repeaters ripped out, fuel flap bent, rear wiper ripped out and rear tyres were let down thankfully rather than slashed. Seems like they must have been hacking your car for a while considering the amount of damage done. Same as mine, take a few minutes to let the tyres down pushing the valves in, so they must have been there a good 5 minutes.
I too had CSI come along and dust the car off. I spotted a lovely hand print that the lady missed, had most of the fingers clearly visible and a very clear thumb print on the bent fuel flap. However they didn't find any matches, but it's not the end of the world if they don't, those prints are stored on record and if and when the guys are arrested or anything (could even be drunk and disorderly) 10 years or so down the line, they will be identified and the prints for this incident (remember, 10 years or even more on!) will still be there, so they will be charged with that too! I'm keeping my fingers crossed that something does come back although it's been 2 yeas now.