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Could I get one [taxi/car] for tomorrow morning?
Literal
Tomorrow [possessive-の] morning 1-vehicle please-can?
The counter 台 counts machines and vehicles. 一台 here is almost certainly a taxi or rental car being requested from a hotel concierge or dispatch service. お願いできますか is a polite, tentative request — literally 'can I ask?' softer than お願いします. Everything the speaker wants is implicit except 'one vehicle, tomorrow morning' — the listener fills in the rest from context.