Court documents reveal that Mittal then started asking him whether he wanted to touch his penis.
The boy repeatedly said no.
Mittal then lifted up his jeans and the boy, put his hand down the older man's pants.
He later explained that he was worried about what would happen if he did not go along with Mittal's lewd suggestion.
In March 2017 Mittal pleaded guilty to one charge of doing an indecent act on a young person.
In August 2017 he was sentenced to two months' community detention and 12 months' intensive supervision.
Mittal appealed for a discharge without conviction but that was rejected by Judge Philippa Cunningham.
Judge Cunningham acknowledged that Mittal may have felt like the boy was "a willing participant because he put his hand down the driver's pants".
But she said the boy's repeated refusal to do so previously satisfied her a crime had been committed.
"While he did not compel (the boy) to do so under any direct threat of force, I am satisfied that (the boy) did not consent to what happened," she said.
"Rather, in his mind and because Mr Mittal was in control of the car he was afraid what would happen to him if he did not."
After sentencing Mittal filed an appeal against his conviction, sentence and Judge Cunningham's refusal to grant the discharge.
The Court of Appeal decision was released today.
"The appeal is brought on the ground that the judge understated the likely consequences of a conviction and, in particular, that she failed to appreciate that it was inevitable that Mr Mittal would be deported if convicted, rather than deportation being a 'real risk'," the decision said.
"As a result of this, counsel for Mr Mittal on appeal, Ms Thomson, submits that the Judge erred in determining that the consequences of a conviction would not be out of all proportion to the gravity of the offence."
A judge may grant a discharge without conviction if the direct and indirect consequences of a conviction would be out of all proportion to the gravity of the offence.
In determining whether the consequences would be so disproportionate, the judge must assess the gravity of the offending having regard to the aggravating and mitigating factors of the offending and offender; identify the likely direct and indirect consequences of a conviction; and then assess whether the latter are out of all proportion to the former.
In Mittal's case, Judge Cunningham considered the offending in itself "moderately serious" but gave him credit for his prior good character, his diligence in his studies and employment, his marriage, and the fact that some of his children were born in New Zealand.
"She recognised that deportation 'certainly is a real risk' and that, if Mr Mittal were not deported, a conviction for the offending would be adverse to Mr Mittal's prospects of gaining employment in particular fields," the Court of Appeal decision stated.
"The judge, however, was not satisfied that these likely consequences of conviction would be out of all proportion to the gravity of the offence, and she declined the application accordingly."
Following his conviction, Mittal was served with a deportation liability notice.
He appealed that, but the Immigration and Protection Tribunal recently dismissed that and Mittal will shortly be required to leave New Zealand.
The Court of Appeal judges stood by Judge Cunningham's decisions.
"We do not accept the submission that the judge erred in the manner suggested," they said
"We are not persuaded that she did and indeed agree that the likely consequences of conviction are not out of all proportion to the gravity of the offence.
"This was 'skin-on-skin' offending committed against a 14-year-old boy entrusted to Mr Mittal's care for a confined purpose.
"Mr Mittal may have thought he had (the boy's) consent, but consent is not a defence to the charge, nor did the judge find that Mr Mittal reasonably formed that view.
"It follows that we dismiss this appeal."
