Car hit whilst parked, no contact details

Hi all,

Last night whilst my car was parked at my local forest car park, the nearside front wing & bumper has been damaged, presumably by another vehicle hitting it. There was no note left, and I couldn't find any witnesses to the accident. I'm fuming still, to say the least!

So some advice, do I contact the police to report, or just go straight to my insurance company? Not sure what the police would be able to do, if anything? Not happy as it looks like I will have to fork out my insurance excess for the repairs, even though it was not my fault.