Mazda’s capital deployed motorcar bill of absorbing Doctor X, for one (9,8)

'mazda's capital deployed motorcar bill' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'of absorbing doctor x for one' is the wordplay.
I cannot really see how this works, but
'of' could be 'o' and 'o' is located in the answer.
'doctor' could be 'gp' (general practitioner) and 'gp' is found in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?