They are all over Berlin as rentals, which you can rent from your phone, and pay per kilometer. People can test drive them easily, and they are not super nice cars. We much prefer the Audis, Toyotas, and Volkswagens that are also in the pool.
The VW group sells 13 different vehicles built on the MEB platform. The id.4 alone sells comparably to the Tesla Y, but if you consider all 13 the same car they are far and away the best selling car in Europe.
Considering all 13 the same might be a stretch, but if you just take the 6 that are the same size as the id.4 you still end up with the same result.
The VW, obviously. With most parts shared across 13 models and all models static for at least a year and usually longer. Plus VW has a good history of parts availability.
Tesla on the other hand is famous for both making minor changes to their vehicles pretty much continuously and a bad history of parts availability.
1M cars over 13 models mean you’ll have no parts at all. 10M identical cars means there’s massive third party supply. Parts are already cheaper than Toyota’s.
I have hosted the models (mostly regression and random forest) WV use to predict missing part availability at their dealership in 2018-2020 (considering sales in the area, average fabrication/delivery time, likeliness of the part having to be replaced, probably others).
I guarantee you that even if I don't like their car, their dealership will very likely have the part you need around the time you need it. It's not the only car-adjacent company that does something like this (Valeo for sure does it too, i worked with them also), but I'm pretty sure it's the only one who has an internal data scientist team working on it.
... What makes you think a VW ID.4 is obscure? I think it's usually the best-selling electric car in Europe. You see way more of those with recent (last few years) registrations in Dublin than Teslas.