A car enthusiasts' meet at a Coburg drive-in cinema has been marred by a hit-run, after a driver doing a low-speed burnout allegedly mowed down a traffic marshal.

Police said one of the shows' organisers was directing traffic at the end of the event off Newlands Road on Saturday when he was injured, despite the meet spruiking a "no skids, no stupidity" policy.

Event organisers for Downshift Melbourne had taken to social media prior to the event to warn patrons to behave at the event which promised "tunes, food, rad cars", and a "chilled afternoon".

"The idea is to have like-minded, respectful, appreciative people there, who can also follow some very basic rules," the group's Facebook page said.