Morgan Allkins and Michael Matthews held a knife to the throat of their victim – who had been tricked into meeting another member of the gang through a dating site.
The trio demanded he give them the car or he would be stabbed.
The man in his 60s got out of his Mazda MX5 and handed over his keys, with the thieves then driving off.
Police were called and armed response units stopped the car shortly afterwards following a brief pursuit. The trio tried to run off, but were arrested nearby.
Allkins and Matthews were identified as being the two men who got into the back of the victim’s car and threatened him with the knife – while the youth was found to have been the one speaking to the victim online.
The trio were subsequently charged with robbery. Allkins and Matthews appeared at Derby Crown Court on Wednesday 28 June for sentencing after admitting the offence, which occurred on February 19.
Allkins, 21, of Portland Street, Derby was jailed for four and a half years. Matthews, 21, of Harrison Street, Derby, was jailed for five years and three months.
The teenager was given a referral order after appearing in the youth court.
