By Evan Dawson, Finger Lakes Editor There is a reason that used car salesmen have a poor reputation with car buyers. "This car is practically in mint condition! And this one is a steal! You can't go wrong with this car, either! They're all gems!"   More and more you wonder if the wine industry is taking its cues from the used car industry. "Rough weather? No way — we reached optimal ripeness again! The growing conditions were ideal! The wines are all a dream!" But when you read the newsletters from McGregor Vineyard & Winery on Keuka Lake, and…