Lamborghini has been hemming and hawing over the production prospects of the Estoque concept ever since it was unveiled last year at the Paris show. With a front-engine, four-door layout, the family-sized Lambo wouldn't be able to share much with either of the company's current models. But with Porsche and its new Panamera now under the same corporate umbrella – to say nothing of the upcoming Audi A7 and Bugatti Galibier concept – the prospects have...