The duo, whose connection dates back to their time in the United States when Miedecke raced for Ambrose's team, will tackle the popular production car enduro in a new Ford Mustang GT prepared by Garry Rogers Motorsport.
Employed by GRM as its competition director, Ambrose has made clear the Easter weekend event will be a one-off return.
“I go back a long way with the Miedecke family, George came and raced in the [NASCAR] Late Model programme with us while I was racing NASCAR, and I know Andrew [Miedecke] from way back too,” said the two-time Supercars champion.
“I was proud to say yes, I'll come and celebrate the past with them at Bathurst.
“We've built this new Mustang and we're really excited to get it on the track. The 6 Hour will be a fun race to do and to get back behind the wheel will be celebrating not only the car build, but my long relationship with the Miedeckes.
“George is a fantastic person. He really came close to making it in the States – he's a pro driver who never quite made that last jump.
“We [GRM] are part of the car build, I've been part of the project throughout the build and hopefully we're going to be a contender.
“It's not a comeback – it's a celebration, to be with George and Andrew and the Miedecke group and I'm looking forward to it.”
“It's a long way from crashing on Marcos' couch in America to where we are today,” he said.
“He and I go back a long way and racing for him in the US was an incredible part of my career.
“We established a team and in the first year took out the pole position award, highest ever international driver in the series and rookie of the year. Unfortunately, we couldn't go on with it then, so this is a continuation of that effort – it's great to be able to do it.
“We're both incredibly competitive people so we're not going there to do half the job – we both want to have a proper go at winning and I think we have the tools and experience to do that.
“It will be great to share a car, especially a Ford Mustang, with him at Mount Panorama.
“Garry Rogers Motorsport have built an incredible car and all the makings are there for a really strong weekend this Easter.”
A capacity grid of 70 cars will be in action at the April 15-17 event at Mount Panorama.