I did a reservation via CarTrawler. I needed to change the main driver.
Official reservation was already ongoing and it was impossible for sixt and CarTrawler to change the main driver without me the official main driver having my physical card with me.
I had to spent time on the phone with CarTrawler responsible for the main booking. And sixt gardemoen accept after e-mails was exchanged between CarTrawler and sixt gardemoen. To finally get the car and swap the main driver.
The nice and very effective girl at the desk was Katja. She was charming and very helpful.