Sharpe, who strangled his former partner in 2000, had been released on licence from prison in 2013, for which he had been given a life sentence with a minimum term of 11 years.
Months before the abduction, which took place in the early evening on 18 May, Sharpe used his mobile phone to record acts of apparent reconnaissance while he drove, said prosecutor Alaric Bassano.
In one such recording, a male voice declared “the abduction point would be here”, the court heard, while Sharpe went on to search on his phone for locations of secondary schools.
Sharpe initially sought to “fob off” his teenage victim with a fictitious story that he had been asked to take her as her father owed someone money.
He asked her lots of questions about herself in an apparent attempt to calm her down, said Bassano, and she obliged “in the hope that by giving herself a personality the defendant would be less likely to harm her”.
Bassano said: “It was impressive reasoning for a young person in her circumstances but an early indication of the fear which she harboured.”
Sharpe bound her wrists and ankles with neck ties as he drove to various secluded car parks.
He made numerous attempts to force her to drink a “yellowy liquid” which she, at times, pretended to consume, the court was told.
Bassano said: “During her imprisonment (the victim) feared that she was going to die, a fear which prompted her to deliberately deposit her DNA in the car to assist police in any subsequent murder investigation.”
Police were first alerted when a dog walker reported hearing a young female crying in a church car park in Knutsford and an older male stating “take a drink”.
The vehicle had gone by the time officers arrived but was later traced to a hotel car park in Knutsford, where the teenager emerged “visibly shaken” and “shocked”, and Sharpe was arrested.
He told detectives he had not planned the kidnap and was “overwhelmed because he had no electricity at home”, was on the verge of receiving a driving ban and had resigned his job.
He added he wanted to talk to a stranger before he killed himself.
Sharpe pleaded guilty at an earlier hearing to various offences including kidnap, kidnap with intent to commit a sexual offence and sexual assault.