The Motor Insurers' Bureau (MIB) will contest a county court ruling regarding the uninsured driver who crashed a car in 1997.
Guildford County Court awarded as yet undecided damages, with a 45% reduction for contributory negligence, to the child of a passenger in the car who died.
In 1998 the driver pleaded guilty to causing death by dangerous driving and driving while uninsured.
The MIB admitted the circumstances of the accident, but alleged the boy was aware the driver was drunk and had been smoking cannabis.
The MIB also alleged the boy failed to wear his seatbelt and was aware the driver was uninsured.
The judge found for the MIB that the boy knew the driver was impaired by alcohol and drugs and that he failed to wear his seatbelt.
But the judge said he was not satisfied the boy had known the driver was uninsured.
MIB technical director Roger Snook said the MIB would appeal on this point.
He said the pair had been driving in a stolen car before obtaining in a questionable manner the car in which they had the accident.
He said the MIB would allege there were uncertainties over the child's paternity. "The questions of any real dependency is highly debatable," he said.