Magna Steyr developed Mercedes-Benz's "4Matic" four-wheel drive (4wd) system, and assembles all E-Class 4Matic models.[citation needed] The company also undertook substantial development on the BMW X3 and manufactured all original X3s (model code E83), and the Aston Martin Rapide. The company developed several cars on behalf of manufacturers such as the Audi TT, Fiat Bravo and Peugeot RCZ.