Local Business listing and approximate addresses

[mdfields]

I have a business with 1 physical location that serves multiple cities and towns in a state. I would like to have a Local Business listing in each of these towns, not just the one town in which I am located.

I have noticed that several of my competitors have listings in other cities, with no physical address listed. It states that their address is approximate.

I also have an AdWords account, and for each of my add groups when I try to add a Local Business Add for each town, It wants to revert to my add stating my real physical location.

How do I add listings with an "approximate address" for each town that I service?

Thanks