Hi @RThomazelli,
HubSpot forms aren’t well suited for this, unfortunately. Forms are not dynamic in the sense that they would adjust to the amount of vehicles. Contacts would have to submit the form multiple times which is not ideal. For a better solution, you’d have to code something from scratch, based on the HubSpot forms API.
You could consider using custom objects for fleet management but I’m not sure whether integrating a fleet management solution would be more feasible. Custom objects would unfortunately not solve the challenge of the input in forms either.
Best regards!