Contact carhirecroatia.com
Send a message about a car, a pick-up or a route and the reply comes by email. For anything about a confirmed booking, include the name on the booking and the pick-up date.
Some things go elsewhere under the rental conditions: a ferry crossing to the islands is arranged with the booking partner's help desk before you complete the booking; for a trip outside Croatia the cross-border option is added during booking, for a fee, and the permission is arranged by email with the booking partner's help desk; and an extension or an accident goes straight to the rental agent.
The form sends your name, email address, any dates you give and your message, and nothing else; the privacy policy says how long it is kept.