Yup, sometimes using genuine parts is required.
The Coastguard Hilux is sourced through a commercial vehicle leasing setup, originally they specified it should go to the Toyota garage, which is way off our response 'patch' (40 mins), the local garage is good, and only 5 mins away. they had to agree to use only toyota parts but got the official servicing contract.
Since that, my mother's Honda has been serviced there during the warranty period, again using genuine parts. The garage has a good relationship with the dealerships, they have no problem sourcing parts, and they're at good prices too. I think it definitely pays to find/stay with a good independant garage.