The leading rental agents such as Eurocar, Maggiore, Avis and others have roadside assistance included in the rental prices. The others do offer it at an additional cost. This is a 24h service that will allow you to call in an issue, to which the rental agency will send out an affiliated company to assist you. Be sure to read the fine print for each agency to see what role you play in the process as most will ask you to remain with the vehicle until help arrives to ensure you are not in breach of any contractual agreements. Search car hire on KAYAK