The event is moving from Birmingham's NEC to London's ExCeL for July 2006 and has pledged a 'new visitor experience' as organisers aim to widen its appeal.
Seventy Seven, Fishburn Hedges' consumer arm, will target the lifestyle media. Fingal, while the Fulham-based firm formerly known as MPA Fingal, will target the motor press.
Tickets for the show - which will host a 2.2km test-drive track, late-night openings and concerts - go on sale in November.
The agencies were appointed by Society of Motor Manufacturers and Traders and show organiser International Motor Industry Events Limited.