Called "Operation Gridlock" by its organizers -- the conservative groups Michigan Conservative Coalition and Michigan Freedom Fund -- the protest lived up to its name, with honking vehicles choking Lansing traffic for miles.

"I have a small business, and (the governor) shut me down, protester Tom Hughey told CNN affiliate WILX . "I work at Ford Motor Company, and that shut down. I realize how important this virus is, but now we're getting to the point where we're shutting too much stuff down."

Gov. Gretchen Whitmer last week extended the state's " Stay Home-Stay Safe " order through April 30 and added more restrictions, including prohibiting most residents from going to another residence unless they were caring for a relative or dropping off a child.

Michigan has more than 28,000 cases of Covid-19 , the fourth-highest number in the nation, with the third-highest number of deaths -- than 1,900 -- according to Johns Hopkins University.

"We have a unique challenge here in Michigan, and it requires a unique solution," Whitmer told CNN's Erin Burnett, pointing out that Michigan isn't the third-biggest state. "We have to be really aggressive here in order to save lives."

Monica Monzo, a protester who said she works in health care, told CNN that "restrictions should have been put on the people that are sick, that are coming down with the illness," but that those "at a lower risk" should be able to continue working and get on with their lives.

"There's no cure, there's no vaccine, it's incredibly contagious and it's deadly," Whitmer responded on CNN. "The worst part is that you can carry it for a week without showing a symptom. Some people are completely asymptomatic. What could manifest in fever or some sore muscles for one person in the household could be deadly for another. And that's precisely why everyone needs to do their part."

Not all protesters stayed in their cars, and groups of people could be seen on the Capitol grounds.

"I think every single person here is probably going to get coronavirus, we're all within six feet of each other," Nick Somber told WILX.

"We'll never know the precise number of Covid-19 cases that come as a result of this gathering, but we know there will be some," Whitmer said. "There are definitely people that are asymptomatic, functioning in society, that continue to spread the disease."

"We're seeing continuous positive tests, and it's precisely events like this that contribute to how long we're going to have to be under the stay home order that they were protesting," the governor said.