Your question simply has two parts, both of which are easily answered
(1) Buying a new car is so far from the realm of fiscal sanity, that you can just totally dismiss it.
It's not even in the ballpark of reality - forget it.
{Before going even any further, note that the insurance you must have on a new purchased/leased will crush your financial life.}
{On that - it is perhaps best to dismiss any answers on this page which don't mention the insurance issue on car purchases/leasing - one of the primary reasons "new cars are insanity".}
My rough calculation is always that: sure, as an absolute luxury for high earners, it's fine to throw away money on a new car. In short, don't even think of a brand-new car unless your family income is over US$350,000 a year.
(2) Regarding your current car. It's only 13 years old and has no mileage.
With modern technology (and this is incredible) cars as new as yours and with as little mileage as yours, drive exactly the same as a brand new car which just rolled off the assembly line.
{For example, one of our cars is a 15? yr old Toyota minivan which has 250000? miles. I paid a few thousand $ for it. It drives literally exactly the same as a new Sienna just off the assembly line. Exactly the same - literally EXACTLY as reliable, smooth, fast and quiet. The only advantage of me walking in to a dealer and buying a new $50,000 Sienna would be that .. it has been washed. Siennas are perhaps the best-engineered vehicle ever, but this applies to all modern vehicles - we live in amazing times for cars.}
Indeed as a curiosity, an acquaintance bought a recent model Sienna for $25,000 and it happened to need a $1500 repair in the first year. Our one needed a $600 repair in the same year. Recall that my one is utterly, absolutely, perfectly, identical in terms of speed, reliability, quietness, smoothness and luxury crap. Hence, friend threw away $23,000 (could have bought my one for $2000) and (by bad luck) $900 on repairs. Admittedly, friend's one is, or at least was for a few weeks, extremely clean. (The dealers wash used cars before they sell them.) Also, friend happened to scratch the back of his one. My one has a scratch, but it's a smaller scratch.
So for better or worse you can dismiss the idea that another car you buy will be "generally better".
- Your car drives as-new, the next one you buy will drive as-new, and
- the cost of repairs is unfortunately down to luck.
It is true that some cars are "just bad luck" and you seem to be forever repairing them.
So, it could be that you are unfortunately spending a bit much each year on the Impala - you're spending say 2000 a year whereas if you have a "good luck" car there's only 500 or 100 a year in repairs.
That will happen. It's random. Unfortunately there is just nothing you can do about that.
Unfortunately too, you suffer the "better the devil you know" factor. If you dump your car and buy another similar car (for say $4000 .. whatever), maybe it will never have a repair, or maybe something will go the first week. Unfortunately, it's impossible to guess.
Purely FWIW as a "car guy guess", I personally would dump this Impala, and buy some new used car (for, say, 4000 - 4500 bucks).
But many, many people would say "800 for a fuel tank, so what? pay it and you have a new fuel tank!"