Along with art director Stewart Byfield, the Victorian marketing executive was tasked with writing a commercial in 1989 for the TAC that would "upset, outrage and appal" drink drivers.

With the road toll trending towards 1000 deaths per year, Mr Harper envisioned a credible campaign that would scare viewers into taking the issue seriously.

"Not just convincing acting, but a sense that our audience had seen the real thing," he would later recall to Campaign Brief. "Experienced real trauma. To shock people and force them to think about their own attitudes and behaviour, we learnt that we would have to provoke a highly emotive response."

The result was Girlfriend, an "all risk" commercial for the TAC. The advertisement was shot at the Royal Melbourne Hospital in the middle of an active emergency department using a real medical crew. It depicts an injured young woman is taken through the emergency ward following a car accident caused by her alcohol affected boyfriend.

"It was all just allowed to happen, screaming, trauma, the lot.", Mr Harper said. "All who looked at it (including research groups) were genuinely upset."

Closing with the Mr Harper's transcendent tagline, the commercial had an instant impact. In the following 12 months, the road toll dropped 37 per cent.

Girlfriend was the first in decades of advertising campaigns by the TAC incorporating the tagline, which has reached millions of drivers around the world. In 1998, one of the TAC spots won Mr Harper Best of Show at The One Show. It was the first Australian advertisement to take top prize at the prestigious international show.

Mr Harper would also win three FACTS/ATV Australian Commercial of the Year awards over the course of his storied career as partner and creative director at Grey Advertising.