frog1520 said:Who can do that, and how much would it cost?
I agree joe public might not have easy access to a forensic lab , some colleges and universities have labs and if you have a contact there , they may be able to help ( Cardonald College here in Glasgow do evening classes in forensic science with the participants being able to use their labs ) . Vehicle paint manufacturers will also have well equipped labs . If one of the vehicles involved had an unusual paint colour , you could even go down to your local automotive paint supplier and match a sample using their colour matching charts .
As for 'scraping' paint off the other vehicle ; that's not what I meant . You will have some of the other vehicle's paint left behind on your car - recover a sample of that . On the other car , there was apparently some transferred paint from whatever vehicle it was in collision with - that transferred paint should flake off quite easily without doing any damage ( that area will be already damaged so not as if you're doing any harm anyway ) . Just don't get caught doing it in case the car belongs to a big guy

As for costs of analysis - no idea - but if you come up with the goods then yours or the other party's insurance should reimburse costs since they should then be able to claim off the perp .
All depends how sure you are .