By night, Brian Johnson sings in the biggest rock ''n'' roll band on the planet.But by day, AC/DC''s charismatic, flat-capped frontman gets to indulge his passion for all things automotive.Cars and rock ''n''roll, they were made for each other.Car racer, car collector and all-round car enthusiast, Johnson is an incurable, certifiable petrolhead who can''t remember a time when four wheels didn''t feature as large in his life as music.Starting, as a young boy growing up in Tyneside, with an old steering wheel and his imagination, a lifelong passion took root early.And through cramped teenage fumbles in an old mini and clapped-out, hygienically challenged tour vans, to chauffeur-driven, leather-trimmed limos and a sideline as a successful racing driver, it''s been there ever since.By turns, surprising, joyful, poignant and usually laugh-out-loud funny, Rockers and Rollers is the story of man with an insatiable appetite for life and a glimpse into the extraordinary world of AC/DC, set soon