We ordered a car for 7am and didn't realise that we would need to wait 20 minutes for the car to be ready. We are still unsure if this is common, or just that we are unlucky.. We realise we booked right as they opened but we thought, considering it was an option on their website, it would mean the car would be ready at 7am.. Not 7:20. It did actually make a big difference, as we had to be somewhere at 8am.
When we picked up the car we knew we had to pay a deposit, but we didn't think it'd be 500 euros! We were dumbfounded. Luckily we had the money in our accounts to pay it. We had initially thought the deposit would be closer to 200 euro.
Nevertheless, the car was fairly clean (not amazing but not disgusting either). There were a lot of scratches and marks internal and external but the company had a compiled list of everything so we were pretty reassured that we wouldn't be accidentally blamed for anything we didn't really do.
We decided to drop the car off after hours (busy day), but they didn't give us instructions when we picked the car up on how to do so. We don't speak German, but luckily we were able to translate the instructions at the drop off location.
I think the problem here is really just a lack of communication. Communicate the fact that cars aren't available right as you open, don't make it an option on your website if they aren't. Communicate to your customers how to drop off after hours, so they aren't stressing out, and communicate the deposit!