The wheel arch fenders and integral wing panels on the new Audi A2 are
made from a compound comprising polypropylene and filler, plus a
polyolefin elastomer from DuPont Dow, called 'Engage'. Though somewhat
unconventional for this type of application, the addition of Engage adds
several important properties, including a reduction in the compound's
coefficient of linear thermal expansion to around that of steel and
aluminium, plus high impact strength. Used as an impact modifier in this
particular application, Engage can also be added to compounds for
moulding and extrusion, where it reduces weight and increases low
temperature resistance.