Financing is running out – how is it best for me?

Hello! I bought my Audi A3 8P 2.0 FSI by financing about 2 3/4 years ago. Now I have to pay a shooting rate of 15,000 euros after the 3 years financing period. Now I only wonder if it’s worth paying the 15,000 euros or if I drive differently better. First of all to the data: My car is an A3 8P 2.0 FSI S-line with extras like Xenon, light sensor, rain sensor, coming leaving home, climate automation, Concert 2,…). I drive about 30-35,000 km, ha b so already almost 90,000 km on the clock. Therefore I also have doubts whether the car will last the next time without expensive repairs. At first I thought of three possibilities: 1. I pay the final rate – the car belongs to me and I drive it for a few years. 2. I pay the final rate – the car belongs to me and I sell it immediately private or to a dealer and then buy a junior used one. 3. I return the car and buy a car I am also thinking about whether it is not cheaper to switch to a diesel, because of the high mileage per year. But you can hear that a diesel doesn’t bring so many advantages… If I choose possibility 3, it can be that I also get money back, because the car is in a top condition? Should possibility 1 or 2 be the best, ic can be the best way to do this. h then also get out of the financing contract prematurely? Then maybe I save some interest? Questions about questions! I hope I can give myself recommendations! Greeting, Tobi