A purpose built EV gets something like 270Wh/mile in near perfect conditions little alone in a colder climate like Sweden.
12.5 * 270 = 3,375
So we've made absolutely every assumption greatly in his favor and we're already 750Wh short.
The math ain't mathing.
Edit: Never mind, “hybrid station wagon”.
Even then, he said hybrid.
You can play around with assumptions, like what if it was driven in stop-and-go traffic at very low speeds? Then your quoted 270Wh figure might be lower.
But anyways, with these general conditions, with the numbers you quoted, and with a 10 kwh battery (aspull), you'd be looking at a net loss of 775Wh/day, which means you could go 13 days between charges.
The point I tried to make, is that solar panels on hybrids/EVs add a lot of practical value to people who can't charge at home/work, and it's not just meaningless greenwashing.
Also that 2.6kWh figure is a yearly average probably, sunlight varies greatly over the year.
I want to see a picture of that.
Apparently 1 kw fits on an extended box van [1]. But I don't now how you'd do it on a wagon without making it look like some sort of Burning Man art car.
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1. https://www.reddit.com/r/vandwellers/comments/1dpcxu4/if_any...
Besides, I just checked out panels, and there's a lot of 500w ones that are appx 1mx2m, these station wagons are huge, easily 2m wide and 5m long, half of it a flat roof, so its not outrageous.
(Driving a full EV, but needing to charge 30+kwh/week, and my small (but larger than a car could fit) home-solar only provides max 20kwh/week in spring/summer.