This site is sneaky. They boast having very low rental fees, however there are many added fees that the actual rental car companies that you pick the car up from can add on. I unfortunately ended up paying 75 EUR extra in fees which were not mentioned as valid fees to be charged in the booking document. I tried to argue this from a lawyer's perspective, stating that the terms and conditions did not allow for any of these fees, but the customer service I received from check24 was horrible and I unfortunately didn't get my money back. Luckily in retrospect the amount was so little. But watch out and definitely don't book with this company! It will cost you more than booking from a respected company!