Expropriating Teslas is possible without a change in the constitution but with a simple law, if they, in the individual case, can be considered means of production (Article 15 GG), though compensation is due. To expropriate under Article 14, you’d have to show that it’s for the public good, which would be a very tall order. It would also be possible to extend right-out seizing (without compensation) to traffic misbehaviour other than extreme speeding.
Article 15 has never been applied, though, so besides how generally pointless expropriating Teslas Elon already made his money with is don’t expect anything to happen before Berlin expropriates large landlords (>1000 flats) for real. Parties are doing their best to not follow up on the earlier referendum so right now the organisers are busy writing their own law which then can be referendumed into being directly applicable law.
You know what we should lobby for? Putting sanctions on Elon. In lieu of expropriating, that’d be expensive, just make him divest completely.
They make no secret out of that, where things get dicey is the role of the Porsche/Piëch clan which ate itself back into the company. That’s also where the “close German factories” drive is coming from, they want their dividends so they don’t have to sell stock to cover some credit or the other.