We were allocated Firefly when booking through Holiday Autos. The broker offers no indication which company will provide the car before paying - in future, I would carefully review the rental conditions (this is possible before booking) as generally the better companies operate a full/full policy. As it turned out, Firefly are a budget arm of Hertz. The vehicle we received was a Opel Meriva with 35,000km on the clock. We were made aware on receipt of the car that we would be charged for a tank of fuel (the rate was surprisingly comparable to most filling stations) and that there is a possible cleaning charge of EUR15. We returned the car as clean as possible without a full interior/exterior wash, and were still charged the cleaning fee. I had to drop the car off out-of-hours so was not possible to get the car seen by a representative. Firefly have no telephone customer services, and there has been no response to an e-mail I sent them a week ago. The local offices refer all problems to Firefly customer services, and almost acknowledged the issue by advising we may have to end up contacting Hertz customer services. Overall I would avoid Firefly, or at least price in sneaky charges.