Booked my car via Rentalcars.com, at a fixed price with full details shown on my rental voucher. When I arrived at Tenerife airport we had the usual hard sell to try and sell me the upgrade insurance, which I politely declined as I have an annual excess insurance policy with insurance4car hire. When this didn't work they then told me I had to pay a diesel excess fee of 38.36 euros. The car only came as a diesel so I refused as there was no mention of this on the documentation. They wouldn't release the car so had to phone Rentalcars who also spoke to the local agent and got nowhere. Was advised by them to pay the charge and they would obtain a refund for me on my return home. So far only a partial refund made by Goldcar. These guys are out and out crooks, cowboys and rip-off merchants. They should be struck off by their governing body as not fit to operate. As with all the other reviews DO NOT USE UNDER ANY CIRCUMSTANCES. You have been warned.