BMW Z4 M40i Convertible - Frozen Grey - Immaculate Condition - Low Mileage For sale is my stunning BMW Z4 M40i in the rare and head-turning Frozen Grey finish. One careful owner from new, meticulously maintained and kept in exceptional condition. This car offers the perfect blend of performance, luxury and open-top driving, powered by BMW's brilliant 3.0-litre straight-six delivering effortless speed and a beautiful sound.