Sears Imported Autos, the big Mercedes dealership that spent $5 million in 2011 to overhaul its Minnetonka facilities, has invested another $1 million to add sales and service of Mercedes Metris vans and Sprinter cargo vans and RVs.

The company said the move is a significant luxury vehicle diversification aimed partly at the commercial market that will get the same treatment as a Mercedes-Benz owner.

Sears' personnel remodeled a former display facility at a cost of $1 million to accommodate the new line with six service bays and a separate crew of Mercedes-trained technicians, service representatives, sales and parts staff; essentially a new small dealership within a dealership

Sears, which has been servicing 70 vehicles monthly since December, expects the number to grow to 150 vehicles during the summer RV season.

The dealership, which sells 180-plus new-and-used vehicles a month, several years ago decided to focus exclusively on Mercedes, selling off its BMW operation, at a time when competitors were diversifying brand offerings. Sears has seen revenues grow from about $60 million in 2010 to more than $100 million since the economic recovery kicked in in 2010. The business employs 110 people.

The late Don Sears, who died in 2011, was a farm boy who came to town and eventually owned a car lot on Lake Street. He bought in 1971 what was then Walker Motors of Wayzata in 1971, an authorized Mercedes-Benz/BMW dealership.

The business today is run by Sears' son in law Don Davidson, also one of the owners with three other brothers-in law. He joined Sears Imported in 1979 as a salesman after a decade in accounting.