Heimgartner won the New Zealand V8 series in 2017/18, in a Richards Team Motorsport (RTM) Toyota, and has previously partnered Hughes in endurance racing.
“I've known Lance for a long time, and have always enjoyed racing with him in the two driver events,” said the Auckland-born driver.
“(I'm) Looking forward to seeing what we can achieve over the weekend.”
Hughes said, “We had a great season last year with Jack Smith joining the team and ultimately winning the drivers championship.
“Having a driver the calibre of Andre in the car will be fantastic. He'll be pretty fresh having just finished the Supercars season last weekend.
“I've always enjoyed having Andre in the team when we did the endurance races together.
“He brings a lot of experience, so with his input I'm looking forward to seeing what sort of results we can get and hopefully have both cars up at the front.”
Meanwhile, New Zealand-based Queenslander Alexandra Whitley has signed on to race one of the RTM Camrys this season.
Round 1, featuring three races, starts at Pukekohe this Friday.