When we went to Ireland in 2023, I also booked with Sixt (although it was way cheaper than your rental for a whole week!) They first gave me a BMW 7 series and I didn't even want to get it out of the parking garage (at the Conrad Dublin location). I went back and swapped it for a Toyota compact SUV which was much easier to get around on the tiny roads out in the country. Hope you enjoyed the Audi. Looking forward to reading the rest.
The advantage is, that I´m used to bigger cars. Enjoy is perhaps the wrong word, but it was OK.