I think it is amply clear to anyone who happens upon this thread who should do the apologizing and who is missing the point. I do not think that I can add more clarity to the matter.

Please register on spritmonitor.de. Your numbers will be very welcome there.

The Lupo has been out of production for a decade and only manages 3.5l/100km in practice.

Yes, if you go at a steady 50km/h any decent car can do 3l/100km or better. That is not a realistic test.

"Redirecting without using fuel" is known as "gravity assist". I mention gravity assist in every single post.

5l is doable in a petrol hybrid, and you can get quite close with certain non-hybrid petrol econoboxes.

I know spritmonitor.de very well. They are one of very few sources of real fuel consumption data. Not silly test data that no one can achieve in practice.

Feel free to provide examples of in-production econoboxes with a 3l/100km fuel consumption under real-life driving conditions.

Compressing gas has a fairly lousy energy return. The air heats up when being compressed, and that heat is wasted unless you insulate the tank.

3l/100km is a myth. See The most fuel efficient vehicles.

The only ones that come close are 2 tiny diesel cars. Both have been out of production for almost a decade.

Accelerating at a modest rate is not particularly an advantage in a petrol car. Petrol cars are only decently efficient under full load, so you want to accelerate quite swiftly, using as high a gear as possible. If you are driving an automatic, it will spoil that idea by "helpfully" shifting down when it detects that you are pushing the accelerator, so that only works in a manual.

Because are wrong. I am not talking about landing on the Sun. You need to get rid of the "horizontal" delta-V of the Earth. "Vertical" delta-V is a non-issue; the Sun's gravity can provide plenty of that, but that only helps you once you get rid of your horizontal delta-V. Otherwise you keep missing.

And yes you only need to get rid of enough horizontal delta-V to strike the outer parts of the Sun. The difference is negligible.

I already address that part of your wordgasm. You can gravity assist to escape velocity, and it is easier since the delta-V is smaller.

Orbits do not spontaneously decay. They stay pretty much forever. Otherwise the planets would have long ago fallen into the Sun.

Yes my numbers were wrong. The conclusion, however, was not. See Shooting for the Sun
If you do gravity assist, you can do that for escape velocity as well.

Hint: Earth orbit is ~100km/s. Solar escape velocity when starting at Earth is ~50km/s. So it is twice as expensive to hit the Sun rather than Alpha Centauri.

Feel free to do so for me. I am right.

There is plenty of desert, and deserts are growing. Set aside a few million hectares, and use the rest.

Besides, if you want to conserve the deserts, putting nuclear storage facilities there would be just the thing. Otherwise a good portion is getting covered with solar panels within a decade.