So the soft franchise is an image thing? yeah I can agree with that. But you already have a loyal customer base? they arent going to stop coming to your garage because its got a fancy expensively designed sign outside now are they? In fact you are after other peoples loyal customer base really? will they drop the other garage because they dont have the sign outside?
We all know there are a certain amount of customers who float around from garage to garage, almost always on price. These customers cant be made loyal, cause next job, its ring round for a price everywhere again. This still applues if the sign outside says 'government approved garage'