More than 260 people have signed up so far to sleep in their cars on the night of June 16 to show solidarity with homeless families.
"Park up for homes Mangere", a Facebook event created on Tuesday night by a group of 10 friends, aims to draw hundreds more to sleep in their cars in a Mangere carpark.
"It's to show that we care, as the so-called 'middle New Zealand', about those in our society who are doing it tough," said journalist Justin Latif, 34, who has lived in Mangere for six years with his wife Joanne, a graphic designer, and now their daughter Isobel, 2.
"We are not part of a group or anything," he said.
"I guess there are some loose connections through the fact that we are all Christians, but we all go to different churches, it's not like it's one church or anything.