SO, WHO’S pushing for a mid-engine C7 Corvette? Not Bob Lutz. It’s Tom Wallace, the fourth-ever chief engineer in the 55-year history of the front-engine, rear-drive American sports car. GM is still far from locking in the next car’s design, he says. While most of our mail, spurred by the November issue’s “Corvette Manifesto” story, seems to be overwhelmingly in favor of retaining the classic layout, Wallace says half his mail is in favor of a mid-engine…Even so, the self-proclaimed king of the Detroit blogmeisters, who earlier this year claimed you could bet your house on the C7 being mid-engined, has now conceded that GM is currently looking at building a mainstream C7 with the traditional layout as well as a limited-edition, high-price, mid-engine, super Corvette. We say GM should…