Kelly Racing effectively represents the final two pieces of the puzzle in the silly season with drives held last year by Heimgartner and Michael Caruso not yet spoken for.
The Braeside-based team enters 2019 without factory backing from Nissan for the first time since it swapped Holden Commodores for Altimas with the advent of the Car of the Future era.
Kelly Racing marketing and sponsorship boss Nick Ryan had told Speedcafe.com that the team was hopeful of achieving continuity in its driving ranks, but that commercial considerations would be a major factor in its decision making.
Only team co-owner Rick Kelly and Simona De Silvestro have been confirmed so far with Garry Jacobson understood to be vying for one of the other seats but Alex Rullo, who joined Jacobson as a Pirtek Enduro Cup co-driver for Kelly Racing in 2018, likely to remain in the Dunlop Super2 Series.
Heimgartner is reasonably confident that he will retain the drive in the #7 Altima.
“I hope to know by the end of this week what's happening, definitely,” the 23-year-old told Speedcafe.com.
“The Kellys are obviously working hard to put me in a car and sort that out but motorsport runs on money and they need to find it.
“We're trying to tie up some sponsors at the moment, trying to get things working, but I should know in the next week definitely whether I'm racing Supercars or not.
“It's still looking pretty hopeful and hopefully I can continue on and have another good year with them.”
Heimgartner inked a deal with Kelly Racing after impressing in a last-minute call-up to Brad Jones Racing for the 2017 Supercheap Auto Bathurst 1000 and Vodafone Gold Coast 600.
The New Zealander took until Race 12 of last year to bag a first top 10 finish in a Nissan but believed his second on home soil proved he deserves a drive in 2019.
He made it three top 10s in a row next time out in Newcastle with his Sunday result of sixth a season-best.
“We're both trying to work towards the goal of me being on the grid next year, and obviously with a strong end of last year we both want to make it work, see what we can do this year,” added Heimgartner.
While he also sampled the new S5000 open-wheeler at the car's launch event at Sydney Motorsport Park, the 2017 Porsche Carrera Cup Australia runner-up says that his focus is on Supercars.
“You always have an eye on other things but at the moment we're solely just looking to return again to Supercars with the Kellys,” said Heimgartner.
While Tekno Autosports has not confirmed its plans, it is expected that Jack Le Brocq, who was linked to the Tickford Racing seat which ultimately went to Lee Holdsworth, will stay at the Yatala squad.
That leaves only Kelly Racing to finalise its driving roster, although Ryan said that the organisation would prefer to firm up sponsorship rather than rush into appointments before the new year.
“We'd love to have everything tied up at the start of Christmas,” he told Speedcafe.com late last year.
“We're really pushing to make that a reality, but at the end of the day, we need to make sure that all the business side of things line up.”
Heimgartner finished 17th in last year's championship, the second-highest in the team, one position and 10 points ahead of Caruso.