Barbie perhaps books a car (6)
I believe the answer is:
toyota
'car' is the definition.
(I've seen this before)
'barbie perhaps books a' is the wordplay.
'barbie perhaps' becomes 'toy' (I can't explain this - if you can you should believe this answer much more).
'books' becomes 'OT' (Old Testament).
'toy'+'ot'+'a'='TOYOTA'
Can you help me to learn more?
(Other definitions for toyota that I've seen before include "Turn to a toy for a car maker" , "Japanese car firm" , "vehicle?" , "Japanese car maker" , "Car manufacturer" .)