The previous Lancer Evolution series were homologated for the Group A class, and their competitiveness against World Rally Cars from other manufacturers was therefore limited.

However, the drivetrain remained the same as before, and when Tommi Mäkinen left the team at the end of 2001, the new drivers couldn't get on with this special transmission, which required an aggressive left-foot braking approach.

It is mated to a 6-speed sequential transmission via a triple-plate carbon clutch and distributes power to all four wheels via front-, centre- and rear- active differentials.

The suspension was also updated to offer more travel and rigidity, and slight changes were also made to the transmission (to suit more the very different driving style of McRae and Delecour).

The bodywork was subjected to extensive aerodynamic testing at the Lola Cars wind tunnel (this resulted in the completely new front air dam, the new wheel arches, and the interesting, shopping trolley handle-like rear spoiler).

The lead Lancer WRC04 in the 2004 World Rally Championship was driven by ex-Peugeot driver Gilles Panizzi, with his brother Hervé as co-driver.