Holden says it has found a buyer for its Elizabeth site, in Adelaide's northern suburbs, but will not reveal who it is.

The last car will roll off the Elizabeth plant's production line in two weeks and the company says the site-decommissioning process will extend into mid-2019.

The future use of the site has been hotly debated, with suggestions including electric car manufacturing and medical cannabis cultivation.

Holden said the successful buyer plans to turn it into an "innovative business park", with industries such as resources, logistics, defence and food and beverage.

It said it will retain a significant portion of the site for a spare parts operation.

While it would not reveal the name of the buyer, Holden executive director Richard Phillips said that they were from interstate.

"They have a good performance record and ability to deliver a high-quality outcome," he said.

Mr Phillips has promised renewable energies would be part of the plan for the site.

He said contracts were still being finalised and the name of the buyer will be released once that process is finished.

The Mayor of the City of Playford, Glenn Docherty, said that it was a positive that the developer was looking to involve industries such as resources, defence and food and beverage.

"[They have] got some natural key strengths for our workers, for workers in the north," he said.

"So it is a good thing that we've got a business park development being proposed and that a purchaser is willing to bring in private investment to get the ball rolling."