It’s as Tim says, but I would add that it’s always been the case that the most expensive cars on the scheme offer the best value and the cheaper cars the worst value, even with ‘normal’ AP’s.
For example, a £20k car with zero AP costs the customer 50% of the cars new price (£10k sacrificed benefits plus £0 AP = £10k = 50% of £20k). By contrast a £36k car with a £2k AP costs the customer 33% of the cars new price (£10k sacrificed benefits plus £2k AP = £12k = 33% of £36k).