Hello Paul,
I run an in house workshop and have experienced the issues you have had, You get the main agents looking down their nose at you one minute then the next they phone you up and ask have you got or can they borrow a certain part or have you had a problem with. Then when you advertise for a job you get these very same people looking for a job from you I have dealt with a Mercedes main agent for over 22 years and they still treat you like !!!!! but they love to invoice you and a VAG dealer that could not be more helpfull Bit like life swings and round-a-bouts Being in house I also look after production machinery (electrical/mechanical and suppliers bend over backwards to sell their products and information to you and you can make more money in this area).
I just guess the automotive industry has never really changed since i've been in it and that has been over 31 years now but I still love it.
Anyway what ever we do it all helps to pay the mortgage. (And don't even mention the marine scene which I also dabble in makes automotive look easy)
Anyway all the best and good luck in your new career,
Ian