Detectives investigating the unsolved murder of 13-year-old Milly Dowler have received more than 30 calls after a fresh appeal for information.
Police say the red Daewoo Nexia car is crucial to their inquiry
Surrey Police said they were delighted with the response and a number of calls had the potential to be significant.
A renewed appeal was issued on Monday after Levi Bellfield, who has been identified as a prime suspect, was convicted of murdering two young women.
Milly disappeared in Walton-on-Thames, Surrey, on 21 March 2002.
Her parents, Bob and Sally Dowler, have appealed to anyone with information about what happened to their daughter, whose body was found six months later, to "find it in your heart" to tell police.
Detectives also renewed their appeal for help in tracing a red Daewoo Nexia car seen in CCTV footage taken in Walton-on-Thames on the day Milly went missing.
Milly Dowler's body was found six months after her disappearance
Former nightclub bouncer Bellfield was interviewed over her death three years ago, and a car of the same colour and model was owned by his ex-girlfriend.
Detectives have released the vehicle registration, N503 GLT, and chassis number, KLATF68V1SB554108, of the Daewoo in an attempt to trace it.
They have also asked anyone who owns a Daewoo Nexia in any colour to check the chassis number as the registration plate may have been changed and the car may have been re-sprayed.
Anyone who owned such a car in the last six years is also being urged to check for these details on their old MOT certificates and other car documents.
It is also possible that the car may have been scrapped, destroyed or placed in storage, and police have appealed to anyone working in scrap dealerships or other vehicle-related businesses to check their records since 2002 for any mention of the car.
The body of Milly was discovered on Yateley Heath, Hampshire, six months after she disappeared on the way home from school in Walton-on-Thames.
Property that Milly was carrying at the time has never been found.
Items belonging to Milly when she vanished have never been found
This includes her Heathside School uniform, black "Pod" platform shoes, a blue Nokia 3210 mobile phone with "Milly" written on the back and a beige and black JanSport bag containing school books and a purse with a playing card design.
It is understood that officers believe they have compelling circumstantial evidence linking Bellfield to her murder.
A Surrey Police spokeswoman said: "Detectives have been investigating Bellfield and the end of his recent trial for offences in London has provided new opportunities for us to explore areas that we had previously been unable to."
At the time he was questioned in July 2005, Bellfield, who ran a wheel-clamping business, failed to account for his whereabouts on 21 March 2002.
But his girlfriend at the time of Milly's abduction owned a red Daewoo Nexia and lived in a rented ground-floor flat close to where the girl was last seen.
The vehicle has not been seen since it was reported stolen from a pub car park in Hounslow, west London, several days after Milly disappeared.
Police know that Bellfield was familiar with Walton-on-Thames and Milly's final resting place on Yateley Heath, as he was a frequent visitor to the nearby Blackbushe car auctions.
Bellfield was convicted at the Old Bailey of the murders of two young female students and the attempted murder of a third in south-west London in 2003 and 2004.
He was given three life sentences on Tuesday.
A reward of £50,000 is on offer for information that leads to Milly's killer.
Anyone with information about Milly's death or the red Daewoo Nexia should call the police investigation team on the dedicated appeal number 01483 637637.