Do not use Cartrawler, they will rip costumers off!
We booked an Avis car through Cartrawler, with a one way fee Gothenborg to Skövde. Due to a change in plans the car was returned at the airport of pick up. Avis correctly subtracted the one way fee in the final bill, but Cartrawler keeps that difference and does not refund it.
Furthermore, they charge 50€ for insurance, compared to Avis for 25€. It is a total scam.
Book Avis directly on their website.