Actually this case can be considered as Hit & Run case. Your
friend should call the police at 999 so that they can road block or
look out for that particular car. Even though if no one is injured,
they will consider as a case.
For now, it may be to late. If not, you can try going to Cycle
& Carriage body workshops and find the car there. The driver
may properly send it to the agent's workshop.
And since you have the first 2 letters of the Subaru, maybe you
want to make a police report at the TP HQ and giving them the
details you have on hand, and since a hit and run, they will
investigate and get something in return.
A year or so ago, a car hit my front bumper at a car park. Then it
drove away. Don't know a kind soul left a note of the vehicle
number on my windscreen. I went to the police station, and they say
no injuries, they don't care. But I told them it is hit n run,
since the driver did not stop and drove away. They cannot tahan me
and make a report. An investigation is carried out and the driver
was charged with careless driving and forgotten, still got one more
charge.