If you want to wait 90 minutes and then be scammed, go for Centauro.

Renting through Centauro was the absolute worst experience I have ever had. Not only did we need to wait 90 minutes - the woman at the front desk told us we needed to have an international drivers license (which was not indicated anywhere) and then told us we could solve the problem by paying 250 euros and then tried to get us to slip her fifty euros outside to solve the problem. Extortion. Awful. Unbelievable that this happened in Europe.