No, during your reservation the car is and always will be available to you.

You pay for the reserved time – even if you don’t actually use the car since it is unavailable to other members. Remember you can cancel your reservation if you have changed your plans. Up to 24h before the start of your reservation you may cancel for free. You will still save 70% if you cancel within 24h of the start of your reservation: the cancelled time will be billed at 30% of the normal tariff (cannot be applied retroactively)

Tip: this also applies when you return the car early. When you lock the car using your cambio card, the remaining time is automatically cancelled.