Since Mercedes-Benz offered the first car sunroof in 1932, roof makers have found novel - and more complex -- ways in which to let the sun shine into the cabin. Continuing just-auto's series of interviews with leading roof makers, Matthew Beecham talked with engineers of Magna Car Top Systems (CTS) about their roof systems business, modular roofs and the challenge in providing a soft-top with a high-quality appearance without any wrinkles or optical impairments from mechanical parts, even after hundreds of opening and closing cycles.