What is the transformer for?
I spent a few years working in a car dealership service area. There were no transformers in the service area. I am guessing this is for a charging station.
I strongly suggest you do NOT put the transformer in the service area. Doing so will run the risk of severe damage. Take a walk through a service area sometime at look at the walls and equipment there. You will likely see damage from vehicles and the machines used to clean the floors with.
If you put the transformer somewhere safe from everyday hazards, you won't be anywhere near a classified hazardous area.
I suggest putting it wherever they have the brake machines and air compressors.