A big issue for most motorists. Not saying all workshops are dishonest, but I met enough dishonest workshops to be wary of everyone.... Personally I always go to a big workshop, feels bad that I am not giving the small enterprises a chance, but big workshops the technicians have no incentive to cheat. They won't bother to give a lower grade motor oil (even though you paid for the better) because they are not the boss. They won't bother to give low quality fluid, parts etc because the savings won't affect them. they may be slightly more expensive than small workshops but I won't get cheated. However, if you do find a good workshop with a great technician, do stick to him. This blog article explains some of the difference in car full servicing, basic servicing workshops stuff.