Which insurance companies are providing finance here?
Of the best selling makes, Hyundai, Ford, Kia, Mercedes, & Peugeot finance is through BoI. Volkswagen, Toyota, Nissan, Renault, Skoda, BMW all finance through brand owned banks. For example, VW & Skoda finance goes through Volkswagen Financial Services AG, Renault & Nissan through RCI Banque.
I have a friend who used to work on the quote engine of one of the larger providers here, they said the calculations are largely based on payout stats. Older cars are statistically more likely to be involved in claims, and pretty much all the suspect claims with large injuries payouts involve older cars.