Okay, you list priorities as gas mileage, interior styling, reliabilty and durablity and a price of $45K, 2 years old, and 50,000 max.
To me there is one option and one option only. The Lexus RX 450h Hybrid. It checks all the boxes, although interior styling is quite subjective as you either like it or not. You can find then for less than $45K near you on TruCar, well under 50,000 miles and two years old. They are very reliable by every measure and EPA gas mileage is 31 city, 28 highway, 30 overall. Near me there are 13 of them, and 9 are under your price point.
If you don't like Lexus are are willing to take a hit on reliablity (although not as bad as it used to be) you could get another Audi Q5 or BMW X3 as they drive differently, have different interiors, and don't offer hybrid motors.
While I own a Buick Envision and I am perfectly happy with it (2018) after one year and almost 19,000 miles, I don't think it is luxurous enough for you considering what you have. I bought it because it is reliable (it had been made for 4 years when I bought mine with proven powertrain parts that were about 7 years old in 2018 and is a light hybrid where the engine turns off at stop lights and signs).
I would avoid anything else as the reliablity suffers (I would not consider them).