THERE was a shortage of 2,000 parking spaces for container trucks, said Secretary for Transport Mr Michael Leung Man-kin. Mr Leung said there were 32,200 medium and heavy goods vehicles registered in Hongkong and regularly in operation, compared with only 30,600 parking spaces. ''To meet the present shortfall, we are identifying more on-street parking in areas of need,'' he said in response to a question from independent legislator Mr Andrew Wong Wang-fat. He added that an extra 300 spaces would become available at existing container terminals. About 2,000 spaces would be provided by the new Container Terminal No 8 by August. And Container Terminal No 9 would offer 2,000 spaces in 1995.