The sort of driver who may be ordered to take cabs! (8)
I believe the answer is:
backseat
'driver who may be ordered to take cabs' is the definition.
'backseat' can be an answer for 'driver' (thesaurus). I am not certain of the remainder of the definition.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for backseat that I've seen before include "Secondary or inferior status" , "driving position - that's critical" .)