Drain cash fund to obtain electric vehicle (4,5)
I believe the answer is:
milk float
'electric vehicle' is the definition.
'drain cash fund' is the wordplay.
'drain' becomes 'milk'.
'cash fund' becomes 'float'.
'milk'+'float'='MILK FLOAT'
'to obtain' is the link.
(Other definitions for milk float that I've seen before include "slow vehicle" , "Vehicle carrying dairy produce" , "bottle-carrier" , "Electric vehicle (which starts early!)" , "Van delivering pints?" .)