Mazda and Fiat have signed a non-binding memorandum of understanding to develop and assemble a new roadster based on the next-generation MX-5 rear-wheel drive architecture.The agreements calls for each to develop different RWD roadsters but powered by specific proprietary engines unique to each brand.Both vehicles will be assembled at Mazda's plant in Hiroshima, Japan, with production for the Alfa Romeo model starting in 2015.'BEST-SELLING ROADSTER'Takashi Yamanouchi, president and CEO of Mazda, said: "Establishing technology and product development alliances is one of Mazda's corporate objectives and this announcement with Fiat is an important first step in that direction. "It is especially exciting to be collaborating with such a prestigious marque as Alfa Romeo on a new roadster based on the next-generation MX-5, such an iconic vehicle for Mazda and recognised as the best-selling roadster of all time."Fiat CEO Sergio Marchionne said: "This agreement clearly demonstrates our commitment to Alfa Romeo and the determination to grow it into a truly global brand. By partnering with Mazda, we will be co-operating with the recognized leader in compact rear-drive vehicle architectures to deliver an exciting and stylish roadster in the Alfa Romeo tradition. "We look forward to a fruitful and continuous relationship."Mazda and Fiat have also agreed to discuss further opportunities for co-operation in Europe.