I haven't booked a hire car for next year yet so I may give Arillas Car Hire a go. This year I hired through "Holidayautos.co.uk" and had a car supplied by Hertz. My only problem was with the fuel, as they supplied it with a full tank, which I had to pay for up front, and then it was then a case of leaving it with a tank as near to empty as possible.
The car hire companies must make a lot of money from doing this, because it always a job to judge how much fuel you require to get back to the airport. I would much rather have to leave a car with a full tank as it was supplied, as most airports have filling stations close by.
How do Arillas Car Hire deal with fuel usage?
I always take a video of the outside of a hire car when I pick it up as "evidence". I was caught in a scam in Tobago once and a video is a good way to prove what the condition of a car was like at pick up.
I am sure that you get better service from a small local car hire firm than a large multi-national.