In the eastern city of Dijon, teens apparently angered by a police crackdown on drug trafficking in their neighbourhood set fire to five cars, said Paul Ronciere, the region's top government official.
Another 11 cars were burned at a housing project in Salon-de-Provence, near the southern city of Marseille, police said.
Overnight in the Paris region, 420 cars were set ablaze, up from previous nights, the Interior Ministry said. It said five police were slightly injured by thrown stones or bottles.
But unlike previous nights, there were few direct clashes with security forces, no live bullets fired at police, and far fewer large groups of rioters, said Jean-Francois Cordet, the top government official for the worst-hit Seine-Saint- Denis suburb northeast of Paris.
Instead, he said, the unrest was led by "very numerous small and highly mobile groups" with arson attacks that destroyed 187 vehicles and five buildings, including three sprawling warehouses.
Gerard Gaudron, mayor of Aulnay-sous-Bois, one of the worst-hit towns, said: "The peak is now behind us."
He told France-Info radio that parents were determined to keep teenagers home to prevent unrest.
"People have had enough. People are afraid. It's time for this to stop."
The rioting started on October 27, after youths were angered over the deaths of two teenagers Bouna Traore, 15, and Zyed Benna, 17. They were electrocuted in a power substation where they hid, thinking police were chasing them.
Traore's brother, Siyakah Traore, yesterday urged protesters to "calm down and stop ransacking everything."
"This is not how we are going to have our voices heard," he said on RTL radio.
Car torchings are a daily fact of life in France's tough suburbs, with thousands burned each month.
Police intelligence has recorded nearly 70,000 incidents of urban violence this year, including attacks on police and rescue services, arson, throwing projectiles, clashes between gangs, joy-riding and property destruction, Le Monde reported.
What sets this unrest apart is its duration, intensity and the way it rapidly ignited beyond the original flashpoint of Clichy-sous-Bois in northeast Paris to become a broader challenge for France.
Many of the riotous youths are the French-born children of immigrant parents. The unrest has laid bare discontent simmering in suburbs and among immigrant families who feel trapped by poverty, unemployment, and poor education.
France's Muslim population, estimated at five million, is Western Europe's largest. Immigrants and their children often complain of police harassment and job discrimination.
Some 1,300 riot police fanned out overnight across Seine-Saint-Denis, as the unrest entered its second week and followed Prime Minister Dominique de Villepin's vow Thursday to restore order.
A commuter train line linking Paris to Charles de Gaulle airport northeast of the capital ran a scaled-back service on Friday after two trains were targeted on Wednesday night. The SNCF train authority said one-in-five trains was running and conductors of night trains were demanding onboard security.
Youths fired buckshot at riot police vehicles in Neuilly-sur-Marne, east of Paris, and a group of 30 to 40 harassed police near a synagogue in Stains to the north where a city bus was torched and a school classroom partially burned, Cordet said.
In Trappes, to the west, 27 buses were incinerated. But the unrest was scaled back from the rioting of previous nights, when bullets were fired at police and firefighters without causing injuries.