All the very best on your venture mate.......Like everyone has said so far, its best to stick to what youre good at
and what you can personally pay attention to.
The Garage I mostly go to now, started off like that but I feel the owner has lost some focus since of late.
I personally prefer to show him the car, get his opinion and then see how it can be done.
I've had instances when my limited knowledge of things, has helped me sort it out on my own, rather than take his
assitants advice.
What I also hate is when someone insists that the problem detected is what he thinks it is and your opinion isn't considered.
That said, you will have to build up your reputation as someone who will diagnose the problem well, so that the relevant
remedy can be applied.
Anyway, All the best again and do keep us posted on progress.