The acceptance fee covers some of the initial set up costs of the finance provider including: costs of credit reference searches (which help protect a customer from potential identity theft) and registering the lender's interest in the vehicle at a company called HPI Ltd (to help prevent their vehicle being sold without their knowledge).
The APR is based on the total charge for credit (TCC) and includes interest and other charges which affect the cost of borrowing - even if they are not payable under the credit Agreement itself. The APR is an annualised rate reflecting the timing of such charges, as well as the rates and amounts. The rules for the calculation of the TCC and APR are set out in the Consumer Credit (Total Charge for Credit) Regulations 1980. The OFT has produced a booklet setting out how an APR should be calculated.
Approved authorised repairers are typically a network of garages whose work and charging structures have been scrutinised and found to be satisfactory by your insurance company. If you are involved in an accident, check your policy documents to see how to find a list of approved repairers, or contact your insurance company for a list of authorised repairers in your area.