The Tickford Racing driver flew to the US yesterday where he has been selected to race for the factory BMW supported Rahal Letterman Lanigan team for the IMSA WeatherTech SportsCar Championship finale at Road Atlanta.
Mostert will drive the #24 BMW M8 GTE for the first time alongside regulars Jesse Krohn and John Edwards.
Click here to have your say on the state of Australian motorsport and go into the draw to win a Kincrome Tool Armour Workshop valued at $11,999.
“I'm super excited to get the opportunity to race the Petit Le Mans for BMW. Although it will all be new, I know I can contribute,” said Mostert.
His GT outing arrives off the back of a Bathurst 1000 that yielded a fourth place finish alongside co-driver James Moffat.
The run was not without a controversial moment as Mostert made contact with Tickford Racing team-mate David Russell coming out of Forrest's Elbow on lap 21.
An attempted overtaking move saw Mostert's Falcon tag the rear of Russell which sent the #6 Monster Energy Falcon he shared with Cameron Waters into the right hand side wall, with the damage causing it to lose 13 laps.
After surviving the incident, Mostert produced a strong final stint to drive away from championship leader Shane van Gisbergen and finish fourth, less than a second behind third placed Scott McLaughlin.
“It was a pretty tough day for us, actually I think we were on for a podium,” he said.
“I don't know what happened in the pits, you come in third, come out fourth or fifth, it's not ideal.
“But it's a credit to Moff, we put him on a hard strategy and he really held his own. He was the real reason why we got a result today, so I can't thank him enough.”
Tickford confirmed it would have a detailed debrief over the team-mate tangle on earlier this week which Mostert took part in before readying himself for a trip to the US.
“It's an absolute shame for the team and it's not the way I want to go out there racing,” said Mostert after the racing when reflecting on the clash.
“I just purely went to the inside, I couldn't go any more narrow, just ran out of room and it's always pretty tight at the Elbow. I'm sorry to Cam and Dave, but it's a tough day for the team, it would have been nice to get them a trophy.”
It proved to be a largely challenging final Bathurst appearance for the Falcon as Mark Winterbottom and Dean Canto finished 12th, while an electrical fault put the Richie Stanaway and Steve Owen eight laps down in 22nd, just one position ahead of the Waters/Russell Falcon.