V8 Supercars have drawn the line at no more than five manufacturers in the championship series after Nissan confirmed it would enter compete against Holden and Ford next year.
Nissan will join the series from 2013, with Rick and Todd Kelly's Kelly Racing defecting from Holden to become the Japanese giant's factory-backed team.
Chrysler is expected to announce in the new few months it will become the fourth make on the grid.
But V8 Supercar head Tony Cochrane says the series needs to be sensible about the number of manufacturers allowed in and five is the maximum they will consider.
Nissan has not competed in Australian touring car racing since the early 1990s, when it dominated with the Nissan Skyline GT-R known as Godzilla winning the Bathurst 1000 twice and dominating the championship.