Workers arrive for their last day on the job at the GM transmission plant in Windsor, Ont. The plant closes Wednesday, ending GM's 90 year presence in the city. (Charlsie Agro/CBC)

Wednesday marks the end of the line for General Motors in Windsor, Ont., the one-time heart of Canada's automotive industry..

Once one of the biggest employers in the border city, with more than 7,000 workers, GM has dwindled over the years to just one remaining plant, which produces its last transmission Wednesday afternoon.

Afterwards, the 500 or so employees still left at the plant near Detroit will gather for an informal drink or two at a nearby community building.

"There's not much to celebrate," said Bill Reeves, president of Canadian Auto Workers Local 1973. Reeves will also be the last president for the union local, which will cease to exist after the plant closes.

"Tomorrow they will be assembling the final transmission here in Windsor," Reeves said. "It will be sometime in the afternoon when the last transmission will roll off the line,"

In May 2008, GM eliminated 1,400 jobs in Windsor and announced it would close the transmission plant by the end of this month.

In May, the company's past and present employees held a large celebration honouring GM's 90 years in Windsor.

"You think you prepare yourself for something like this, but until it's actually here, you get that sick feeling in your stomach," Reeves said on the eve of the plant's closure. "And you're not quite sure how to react.

"It certainly doesn't look like anything is going to be coming to Windsor in the near future in regards to General Motors, which is sad because they have had such a rich history here."

GM still operates three other plants in Ontario — in Ingersoll, St. Catharines and Oshawa.