Avoid as they don't know what they are doing. Booked through them to pick up a car at Inverness Airport and paid everything up front. Got to the airport and Sixt said Holiday Autos hadn't sent the correct documents or information about the booking. Called Holiday Autos and gave up in the end because they were awful. Seemed to go out of their was to be as unhelpful as possible with me having to continually answer the same questions and getting nowhere. Had to pay again in the end. Luckily Sixt didn't actually take the second payment but left it as pending until eventually they sorted it and cancelled the payment.