“Great car, but seemed to have electrical gremlin”
My father had a 2000 Chevrolet Impala. He no longer owns this car (more about this later) but I drove the car often (mostly on long road trips, 3500 miles round-trip). He now owns a 2006 Chevrolet Impala, which I've also driven similarly, and will review separately, but naturally my review will compare/contrast the two cars, since Chevrolet updated the car between these model years, and the two cars are similar but with important differences due to these updates (and some equipment variation, since the two cars have different options).
The 2000 Chevrolet Impala is a very nice car, I think in many ways I preferred it to the 2006 Impala. For instance, the rear seat on the 2000 Impala was very roomy, much roomier than on the 2006 model. It also folded down (even on the base model), whereas on the 2006 you must get a higher trim model to get the fold down rear seat (I think it was an option on the base model in 2000). The fold down rear seat allows you to carry longer items than would fit in the trunk (assuming you don't have someone sitting in the rear on one side). It also allows access to the forward part of the trunk, which is important since both model year Impalas have very deep trunks..even with long arms, you can hardly reach the forward part of the trunk when standing outside the car...sometimes items roll forward that you have difficult time retrieving without climbing inside the trunk (I've had to do this on the 2006 since it doesn't have the fold down rear seat). To get the fold-down seat in the 2006 model you have to move up to a higher trim level, which you might otherwise not want or need the other features that come with that trim.
The 2000 model also has very large side mirrors...they remind me of "truck-sized" mirrors. I remember my first impression of the car when my father test drove it was that the side view mirrors seemed huge to me. They did away with this on the 2006 model...maybe the smaller mirrors are more aerodynamic? But the larger mirrors give you a better rear view, but perhaps they did stick out a bit, which could lead to scraping in tight quarters (like garage door openings or at drive-through bank ATM machines).
The 2000 and 2006 did share some very nice attributes. One of which is very nice highway fuel economy (with the base engine). The cars have different base engines, I think the 2000 had the 3100 V6, the 2006 has slightly more powerful 3400 V6. The 2000 would routinely get around 34MPG on the highway, and was pretty good around town. The 2006 has gotten as much as 39 MPG on the highway (more than one segment of a long trip between fueling stops) but doesn't seem to do as well in the city (maybe as low as 19 MPG). Perhaps the 2006 is more aerodynamic, so the highway fuel economy is correspondingly better? The 2006 also seems more powerful (larger engine) whereas the 2000 base engine seemed quite a bit less powerful, but got much better city gas mileage. I should note that we are not fast drivers, we keep it about 55-60 on the highway; gas mileage would certainly suffer if we drove at higher highway speeds.
Another nice attribute of both cars is simply the higher seating position. My father particularly likes this attribute as he gets older, it is tough to get into many cars (with low seating position compared to the Impala) or Vans/SUVs (with too-high seating that makes you climb up into the seat). The Impala seating hight seems just right for non-scramblers, which includes most of us as we get older...yet fewer cars seem to be built with this attribute than in the past, when "standard" sized cars seemed much more common...maybe Detroit should play up this aspect, as even large import cars seem to make you squat down to get into them.
The 2000 died suddenly on us, with electrical problems my father decided not to have fixed (supposedly about $8000 in parts/labor to fix). Not sure if it was wiring harness, but first air conditioner stopped working (compressor woudn't kick in despite full charge of freon), then car wouldn't crank at all. Rather than get it fixed, my father decided to get the 2006 to replace it. Too bad, I liked the 2000 a bit better than the 2006, but both are nice driving cars, with smooth ride, good fuel mileage (on regular gas).