Ah...marriage does change priorities. Ask me how I know
Having talked to a few indy shops and a Motorsport shop-their verdict was clear to me. <Stay the F away from Audi's especially after the warranty expires
Audi's are great inside but peel away the plastic and reinforcements underneath and it will paint a different picture mechanically. This is in addition to the horrendous DIY nature of these cars. Audi's are not easy cars to work on. My dad had an A4 and most recently a A6 and based on his experience.. he's sworn never to buy an Audi product again. (My dad is mechanically inclined)
Essentially-Keep the most dependable, reliable BMW ever made (E9X M3) and downsize elsewhere. You will regret selling the M3 down the road for sure. Nothing else you buy will reward you as much at the M3 in every aspect of driving.
If your argument doesn't suffice-show her this thread.