Tom,
What else can you do? It appears as though you have set yourself apart very well. Maybe focus on the parking lot, redo your businesses parking spaces. The problem just may be that people don’t pay enough attention. We have a similar set up however we share the showroom, office and waiting room space and the entrance with another business. We just completely redid our front desk space to set us apart. Complete with new flooring, desks and clear signage, A digital menu board offering our services. There is nothing the same about the appearance of my business space and the other, – people still don’t get it. My problem is now on the path to resolved since the neighboring business is out of business. And since I hold the lease it will have to be a very lucrative deal for me to lease the space out again.