Personally I think you're fighting an uphill battle against a nationwide problem with dealerships, you could have the best dealership in your area with the best techs available and still lose the fight. Young ambitious and talented techs will gravitate away from dealerships to make a better living at an independent shop, this is due to dealerships over staffing the repair facility with managers that do not produce income and therefore can not compete with independent shops on wages. Next, you are asking your customers to return to the 'scene of the crime' so to speak, many customers that felt bamboozled by the sales team when they purchased their car will refuse to give a dealership any more of their money and will go elsewhere so you need to make sure the sales department is treating customers fairly. Also, honesty in your own department is important, I recently had a female customer come by for a second opinion because the Chevrolet dealer tried to sell her new tires, her tires had approximately 9/32nds of tread remaining with very even wear and no signs of needing replaced. These types of practices will lose customers fast. Another reason we see customers fleeing dealerships is high pressure sales tactics, good old fashioned friendly customer service will win out every time against an over zealous dealership. Dealerships will not only have to fix all of these issues but they will have to re-train the general public and win back their trust, good luck.