Police want to trace two drivers who slowed down when a 16-year-old boy tried to alert passing cars during a robbery in Surrey.
Officers have released an e-fit of one of two robbers who threatened the boy and forced him to hand over his iPod Touch in Chessington Road, Ewell.
The incident happened just before 2000 BST on 17 October, near the junction with Ruxley Lane.
Det Con Nicky Dell said the victim was uninjured but shaken by the robbery.
The two suspects, both believed to be teenage boys, followed him along Chessington Road next to Horton Park Golf Course before stopping him.
A woman in a black convertible saloon and a man in a black hatchback slowed down as the robbery took place.
"We have issued this e-fit is the hope it may jog someone's memory," said Ms Dell.
"It is a busy road and I am sure someone would have seen something.
"I am still very keen to speak with the two drivers who slowed down when the victim tried to attract the attention of passing traffic."
The suspect in the e-fit is white or mixed race, about 5ft 6in to 5ft 8in tall, slim and between 16 and 19 years old.
He was wearing a purple woolly hat, black body warmer and jeans and spoke with a southern accent.