Hi Alan, I find the vast majority of my customers have no idea what diagnostics is! Which is a bit of a bummer as I've called my company "Auto Diagnostics"! But there aren't many garages around here that have invested in the equipment or the training to be able to do it so I'm hoping in time that I'll get more and more of this sort of work, in the meantime I'm getting by with servicing and general repairs as well.I would love to specialise in diagnostics but as you say customers expect their mechanic to be able to fix anything so that's what I try to do. Having said that I don't do welding, and I'm getting too old now for crawling around under cars with gearboxes out or engines out. Perhaps specialising is the way forward. Regards, Derek