Villarogosa--or as us locals call him, Tony Villar (Ragosa was his ex-wife's name)---is a piece of work. No one likes him here. He's an absentee mayor who once claimed to have filled a million potholes in LA! A million. Even a lib like Bill Maher took a jab, complaining that he can't get his car through all the potholes.
To your larger point, a new city surtax was a stupid idea, especially when there were lots of localities close by without the tax. Eventually, explicit taxes like that drive small businesses (and that's what these dealerships are) out of the cities and into the suburbs. Ask Philadelphia what happened when their various and sundry taxes became so high; the answer is "King of Prussia", a suburban area of corporate centers.
Small businesses need to be helped and given tax breaks. But these businesses that run on their own energy and the hard work of their owners and workers, are very different from huge multinational corporations which have a ton of representation in Washington and get tax breaks that small businesses could never dream of. Washington is giant whorehouse and it's pay to play. But paying a little gets you millions, or in the case of GE, billions. Legal "kickbacks" that come from padding defense expenditures, legal tax loopholes that insure that my 5-figure ass pays more in taxes that GE, and legal maneuvres on Wall Street that allow someone like Mitt Romney to buy good companies, strip them for parts, and fire their thousands of workers. (And Mitt still calls himself a businessman. He's a butcher, not a businessman, and my guess is that he couldn't grow a business with a million dollars and a team of pros helping him.)
The rules are different for small and big business. Villaragosa can't tap into big business, so he goes after the small businesses that make the city economically vibrant. The Fed does the same thing, taxing small businesses to the hilt while dumping taxpayer money into the coffers of the big multinationals and their international shareholders. I would never start a business in LA where Villaragosa could tax it. However, if I were a huge multinational, the boys upstairs would have Villaragosa waive every little tax for me and even provide me with taxes from Angelinos.