Two French families called Renault went to court today to stop the car company of the same name calling its new electric model "Zoe", for fear that their daughters called Zoe will face ridicule.

"We don't want to hear 'It's time for your oil change' or 'show us your airbags'," the plaintiff's lawyer David Koubbi told a court, accusing the firm of "stealing a child's name to compensate for an underperforming car."

"Industrialists, in order to humanise and market products, are turning names into brands. So, if you're lucky, you could end up as pretty pot of flowers. If you're not, as a whip, a vibrating dildo or a toilet brush."

Renault's ZOE, which the firm registered as a trade mark when spelled in capitals without the accent on the final "e" found in the French name, is a small zero emissions car due to be released in 2012.

But the families of two girls called Zoe Renault have received the backing of a pressure group, the Association for the Defence of First Names, to fund a legal challenge alleging breach of privacy and identity theft.

Koubbi claimed in court that once a car firm chooses to use a first name to denote a model, as Renault has done with its Logan, Megane and Clio, parents stop using the name for new children.

And in one case, he said, a young girl called Clio was rebaptised Margot when already three years old to avoid association with the brand.

Renault's lawyer dismissed this, arguing that Ariane rockets, Felix cat food and Anais perfume had done nothing to reduce the popularity of these names.

He also accused Koubbi of hypocrisy, noting that the lawyer and some friends had secured the copyright on the name "Gerard" and were using it to promote the "Gerard awards" for the worst performances in French cinema.

The judge is to give his verdict on November 10.