There are imitation or generic parts which are identical in every way for most types of car, which I know that independent garages can get at HALF THE COST of dealer supplied parts. If there is a warranty to consider when replacing parts, they arent allowed to use these IDENTICAL cheaper parts, which really annoys my local garage, as it can save the customer a lot of money.
One day when I was in the garage, the owner was showing and explaining this very thing to a Ford customer, and he had in his hand two identical parts and they had the identical manufacturers name stamped on the bottom, but warranty regulations dont permit these SAME parts to be used, as the cheaper one hadnt got Ford marked on it . It is a sheer RIP-OFF as both parts had come from the same place.