I experienced two shocking scams when I rented a vehicle with AVIS from Malta airport MLA.
1) Although the Avis website claims that the office is open from 00:00-23:59 they apply an ‘out of hours’ surcharge if you arrive after 19:00!!
2) They fill half the tank with fuel, make you pay a ‘mandatory fuel purchase’ and then instruct you to bring the car back ’empty’. What a rip-off! The island is tiny and I rented a very fuel efficient car; so it would have meant several complete tours of the whole island before getting even close to using up the fuel. The mandatory fuel purchase charge scam is operated by a number of car rental companies in various countries – and I’m sure that they cover themselves in the small print – but I found the Malta one to be particularly cynical.