I realised in a similar, though less detrimental, encounter that true insurance comes in the form of dash cameras. For the equivalent of an insurance payment or two, a high fidelity video of the entire vehicle surroundings can be had.
Honestly though, with a few witnesses and half a plate, it’s a surprise they couldn’t find the car that drove into you. Decerning the colour, and style of car, surely it’d be only a handful of vehicles matching both the description and the numbers.
I’m sorry that happened to you.
Goes to show how strange modern life is that it was easier for them to cut a cheque than send someone down there. Happens all the time unfortunately. I wonder if someone at the impound lot rode it home.