no it was to leave the car there.so when he returned to goldhanger after the murders he could ride home on the bike.you should know that jb could not drive home after the killings in case his car was seen or heard.and even you adam should be able to conclude jb could not drive home in the pitch black without lights.common sense adam.its not well lit city roads.but pitchblack country lanes 
I meant what would he tell Neville and June. That he wanted to stay the night with them. After driving off earlier.
People should just go by the evidence -
People heard him drive off.
He phoned Julie.
No one heard or saw him drive back pre massacre when it would have been quite early.
He brought Junes bike over before the massacre.
He knew how to cycle to and from WHF.
He knew how to quietly get into the bathroom window.
No one saw him drive back to his cottage after the massacre.
The police passed his car on the way to WHF.