He may have won Bathurst nine times but Peter Brock always said that winning the 1979 Repco Round Australia Trial was the highlight of his career. Brock wasn’t a regular rally driver but he loved the challenge of driving on dirt whenever he could.

He'd done the odd rally (one aboard a Holden Dealer Team HQ Kingswood V8), as well as rallycross in the HDT's supercharged Torana XU-1 'Beast', but was comparatively inexperienced in this type of competition against the plethora of rally specialists in the event. 

Brock teamed up with Matt Phillip and Noel Richards to head a Marlboro Holden Dealer Team 1-2-3 in the event. The three works cars were specially-built for the event by rally expert George Shepheard, using six cylinder XU-1 spec engines, M21 gearboxes and 200-litre fuel tanks. Some alloy panels were used to save weight.

Their main opponents were the factory Ford Cortina trio led by Colin Bond. The six-cylinder Cortinas were quick but ultimately fragile. While reports of an unlimited budget from Holden are certainly exaggerated, it was also clear that Ford's commitment to its Repco trail bid simply wasn't as firm as Holden's.

The 1979 event is regarded as the toughest of all the Round Australia trials. Of the 167 entries, only 13 cars completed the 18,885km course in the required 14 days. Most were reduced to scrap metal in the process.