Sixt in most countries is fine. But in Norway they are running a racket. I got charged > 13000 NOK (> 1200 €) for some scratches that were visible only with a magnifying glass, and that were likely already there when I rented the car. The car had scratches all over, although Sixt had documentation of all the others, but magically not the ones they decided to attribute to me. I had bought insurance from Sixt, but that magically did not cover anything. In Norway one expects honesty and one lets down one’s guard; Sixt in Norway takes advantage of that. DON’T EVER RENT FROM SIXT IN NORWAY!!