Patiently waiting for my Aptera. Yup. This is the way.

Most cars won't gain anywhere near 20-40 miles per day from solar, though, they're simply not efficient enough. Get the consumption down, and the same amount of panels can accomplish a lot more.

And, most folks who live in awkward parking situations are also near the city where their commute needs are very short. Folks out in the country who need to drive farther, generally have their own parking and can do plug-in charging. (Probably also supplied by solar.)

ioniq 5 with solar roof promises like 6-7 km a day (4 miles in weird). can we expect an order of magnitude improvement here?

No. The solar panels are likely more than 10% efficient and the battery and motor are going to be pretty efficient. Hitting 100% efficiency on the solar panels is ~impossible, so even if you get really close to ideal on both sides of it you aren't going to do 10 times better.

I guess a wildcard would be making the vehicle lighter.

The Aptera is lighter and can get 40 miles of range from its solar panels on a sunny day: https://www.youtube.com/watch?v=mpiH-Y-HOvE

yeah i'm also sceptical

and that's i'm worried that it's going to be part of a hype to symbolically buy them, wasting the materials to create solar panels even further, only for them to stand in a garage or otherwise well-protected from the sun by the buildings around

Solar panels are getting pretty darn cheap these days. A roof + hood panel system is probably in the low hundreds to 1k per car. And ultimately more panels being sold leads to lower prices for everyone long term due to economies of scale.

There will be some improvement in batteries but the big win will be in EVs that can get 10 or more miles per kWh because then you can get up to 40 miles of range on a sunny day.

The Porsche Taycan only gets 2 miles per kWh. The Tesla Model 3 gets 5 miles per kWh. The Aptera gets 10 miles per kWh.

Aptera: https://www.youtube.com/watch?v=mpiH-Y-HOvE

It doesn't have a hood panel, from what I can tell, so probably double just from that. Then it's a pretty beefy car so lighter and more aerodynamic ones would get more range. Lastly we will get some more battery & panel improvements. So probably pretty easy to end up in the range I gave.

Maybe 20-40 is too optimistic. But even at 10-20 a day that's going to cover a significant amount of usage. It will cut down the fast charging needed from once a week to once a month or so. That's a significant convenience improvement.