David Willey in Rome: "Incredulity at the court's decision"

And being caught doing the act could mean up to three years in prison.

The court made its landmark decision after hearing an appeal from a young couple who had been having sex in their car.

Exhausting: Car sex is described as "extremely uncomfortable"

They had been charged with committing an act contrary to public decency - a lesser offence.

But when they appealed against their $150 fine, the judge decided that car sex is an even more serious crime - an "obscene act".

"A sexual act that is certainly not obscene in private becomes so if it is done in a public road," the judge said.

But according to the court, blacking the car car windows out so no one can see inside might be a mitigating circumstance.

Legs stuck out

Italians - not known to be a shy population when it comes to public displays of affection - are outraged at the court's decision - especially as its national television channels are notorious for taking a broad-minded view towards sex.

Riccardo Schicchi, manager of Italian porn star La Cicciolina, has attacked the verdict.

"Making love in cars has its own history and its dignity. Just think of drive-ins," he said.

The decision could pose problems for many young people in Italy, as they tend to live at home with their parents until their late 20s.

"The verdict is quite correct, but it punishes a typically Italian phenomenon," said author Carmen Llera Moravia.

And another of Italy's most popular writers, Luciano di Crescenzio, said he had never been able to afford to make love anywhere except in a tiny Fiat Cinquecento until he was 30.