With the departure of Michael Hohl from Minden last week, Carson Valley no longer has a car dealership to call its own.Although park-and-sell operations pop up occasionally, an actual sales office with human beings walking balloon-decorated rows of automobiles may be a thing of the past in Douglas County."More than one consumer came up to me last week with that question," said Minden resident Robb Hellwinkel. "It's an inconvenience to have to drive far. But I'm still optimistic about the possibilities."Hellwinkel not only owns the property of the vacated dealership, but represents the third generation of a family rich in …