Car made in four dimensions, reportedly (4)
I believe the answer is:
ford
'car' is the definition.
(Ford is a make of car)
I cannot understand how the rest of the clue works.
(Other definitions for ford that I've seen before include "Shallow crossing point in river" , "Shallow place for river crossing" , "Harrison - - (film actor)" , "Shallow area in a stream where it can be crossed" , "Car - river crossing" .)