You're assuming the lorry driver stuck around.
Don't worry, dear, the police can easily find that out.
You know on which day, at which place and around which time it happened. It shouldn't be a problem to list all companies who made a delivery to that place within that timeframe. Then the officers just have to check the lorries in question for damages or traces of paint from your car (even the best scrubbing can't remove all the evidence). The owner of the lorry will be able to name the driver and - voila! - the police has the culprit.
If your insurance insists, you may have to pay for teh repair in advance but you'll get it back once they found the lorry driver. If it's a really good insurance, they'll pay for you and get it back from the driver themselves.