Infiniti's flagship is extending itself to provide the extra legroom executive sedan shoppers require. This is the new Q70L, available with a brawny V8, AWD and myriad safety technology.Sales of Infiniti’s biggest car, formerly known as the M, have increased significantly this year, boosted by a revised exterior, added safety technologies and the addition of this long wheelbase model. The Q70L expands rear seat legroom by about 5 ½”, nearly …