Sounds like a rolling rental (or subscription). Used to do these with Ford Sierras back in the day, engineers on site for minimum x days, but could be y days, used to negotiate a rolling rental – cheaper than daily rental, but still eye watering. Longest one ran 9 months x 2 cars.
The keyphrase is “Audi have partnered with Onto” Onto are a subscription service.
In life, it's not who you know that's important, it's how your wife found out.