Comment by Snafuh

They are not even in the same ballpark size wise

https://www.carsized.com/en-us/cars/compare/porsche-cayenne-...

But or course you are correct this is not only about American cars. Europeans can build big cars as well.

Cars are taxed by engine displacement in Germany. It's rather low compared to insurance and gas cost though. Indirectly larger cars are taxed through high gas tax.