I need help on a terrible car situation caused by stupid mistakes

So my wife and I own two cars. Mine: 2011 BMW 328i with 76,000 miles and hers: 2013 BMW X3 also with 76,000 miles. The biggest problem is that the X3 is fucked. I mean fucked. The engine had a catastrophic failure that two shops have said I need a new engine. I tried to go the route of looking for goodwill from BMW and they said get fucked, basically. Great, thanks. The cost to repair it is $9,500.

So, I've wanted to replace this car for a while because it's not been to much fun to spend thousands of dollars every year to maintain the fucking thing. Yeah, I'm aware, it's a big no no in the frugal world to buy cars like these. These were mistakes for us. What are my options now. The X3 will be paid off in full in November this year. I could go and pay to repair the car, but I do not have the money to throw at it right now, so I would have to refinance the car. $9,500 to repair the car with a new engine and a warranty on that engine. That's good, but I will still have the same old parts on the car around that could fail and then we would be double fucked. But if we get another 76,000 miles, that might be money well spent? The other side is to replace the car with a used car that has high millage and cheaper to maintain. My budget would be around $15k in order to get something decent to replace the SUV. We would have to take a slightly larger loan to pay for that. Cars in that price range will have no warranties at all, so would that be a good idea?

The next problem is my car, the 328. It's jut too much to maintain. I bought it used for 19,000 and there's only 6,500 left on the loan. It runs fine, but I do spend around 1,500 to maintain it every year on average. Should I just sell it and buy something like a used accord for 12,000?