L-Plater's determination? (7,8)

I believe the answer is:

driving ambition

I'm a little stuck... Click here to teach me more about this clue!

'l-plater's' is the definition.
I can't judge whether this defines the answer.

'determination?' is the wordplay.
I cannot really see how this works, but
'determination?' could be 'gambit' (gambit is a kind of determination) and 'gambit' is located in the answer.
This explanation may well be incorrect...

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I've seen this clue in the Sydney Morning Herald.

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