As a single, middle aged female, I admit to having taken above average care of this car. But after eight years and 86,000 miles, I've not been out a penny on it other than routine maint. I still get regular compliments on it and when I say it's 8 years old, people say, "I thought it was brand new." Planning to keep it, I just had some surface blemishes repaired and am more thrilled than if it really were brand new, since I don't have a $500/mo. Payment to deal with and it's a pleasure to drive still-not fun, but pleasant. I'll have my fun with those $500 on something else.
The quiet of it. I had to drive a rental a few weeks ago and that caused me to appreciate my Avalon doubly. She's never been fun to drive, but always a pleasure. The quiet, the smoothness, the smooth transmission shifting.
I have no suggestions - I wouldn't know how to improve it, unless it were to inject it with some fun, but then it wouldn't be an Avalon, at least not as I know it.