Police have withdrawn charges against a man who was found driving a fake pope-mobile around Sydney.

The car was built as a protest against the Pope's visit and World Youth Day in July last year.

Police charged the driver, Ian Bryce, for distracting motorists and ordered him to take the car off the road.

Mr Bryce says the decision is a victory for free speech.

"I was setting out to inform," he said.

"The purpose of the pope-mobile was the draw the media attention and the public's attention to the false claims and the very bad actions of the Pope and the Church in coming here for World Youth Day, which I believe is in effect a latter day crusade."

Mr Bryce says he had a barrister and solicitor from the NSW Council of Civil Liberties, which he believes persuaded the police to drop the charges.

"It was against the Pope's claims to have supernatural authority, and all the harm he's doing in the world in banning condoms and trying to avoid family planning," he said.

"And now he's said that gays are an equal threat to mankind as climate change, and I can't for the life of me see what harm they're doing anyone."

Mr Bryce says the charge that was dropped was one related to his vehicle being an annoyance to other motorists.

He says he was trying to aggitate attention about World Youth Day and, when asked if he was an annoyance, he replied, "I hope so, I think the Pope is a bigger annoyance."

But he says he was not trying to annoy other motorists.