MIAMI (Reuters) – McLaren have had talks with Audi but are not for sale, team boss Zak Brown said on Friday in response to Volkswagen’s announcement that its Audi and Porsche brands would be entering Formula One. A source told Reuters in March that Audi was ready to offer around 500 million euros ($527.55 million) for McLaren as a means to enter. Germany’s Manager Magazin reported on Thursday that talks with McLaren were close to failing after months of negotiations. Brown, chief executive of McLaren Racing, told reporters at the inaugural Miami Grand Prix that there was no question of any cha…