I AM NOT SURE WHO WAS AT FAULT, WHO SHOULD I CLAIM AGAINST?
Initially a claim can be submitted against the other driver if it is not known who is at fault.
If the other driver’s insurance company does not deal with the claim, then on a without prejudice basis a passengers claim can be submitted against the driver of the vehicle where the passenger was sat.
It is not necessary to blame the driver for the vehicle for the accident but a claim can be submitted to the driver’s insurance company to ask them to deal with the claim on a without prejudice basis (without blame) as you were the innocent passenger.
The passengers can have their claim dealt with even if fault cannot be established between the two vehicles as the passenger was the innocent party.