Is my storage facility name too similar to a nearby facility?

[Josh Collins]

If an existing mini-storage facility is named Madison Storage and I open a maxistorage facility down the street and named it Madison Storage Garages (and the Secretary of State approved our business's name), can the existing facility sue me for having too similar of a name?  

Ok, I know anyone can sue anyone for anything, but do they have a leg to stand on.  They claim it is like naming a fast food restaurant McDonald's Burger Joint.  I also understand that McDonald's is trademarked and Madison Storage is not.  Any quick legal help would be wonderful.  I get to respond to a letter I received from their attorney and I'd like to know the correct questions to ask. 

Thanks in advance....