My local garage will not fit customers parts. 99% are bought blind of ebay some are of questionable quality and are counterfeit. If the chap takes out the gearbox and finds the clutch is the wrong one supplied he has a ramp out of action for days waiting for the new part to arrive. Plus the aggro of these parts failing within weeks and the argument of who is to blame.
Many garages we used to use no longer exist or have changed making owning older cars a nightmare looking for someone who is willing to take on the jobs that can become a nightmare. There are plenty of people on here who are mechanically minded who do wonders with their cars but I am not one lol!
