When it come to repairing your vehicle, whether it be mechanical or cosmetic, you may have the option as to whether you use genuine or non genuine car parts. If the vehicle is under warranty you will have to take it back to a main dealer or recommended repairer to avoid invalidating it, but often may repairs will be covered by the warranty. If you have an older vehicle and take it to a local garage they may give you the option as to what parts you wish to use.
Some people think that genuine parts are always better, but for certain items this is not always the case. Often you may find that the saving you will make on using non genuine parts means that you could actually afford to replace the part again in a few years if required and still have spent less.
If you are in doubt, speak to an independent garage that you trust and ask their opinion. Be aware that if a garage allows you to source the parts yourself and they will fit them, that they will not normally offer you any warranty on that part.