The demise of Tesla sales is a huge deal - a big political deal - in the US.They have been reporting about the dwindling sales of Tesla cars in Europe and Tesla car lots have even been set alight and vandalised in the US. By acting as Trumps right hand man, Musk made Tesla political and a whipping boy for the Republican administration. So rising Tesla = Trump Admin good. Falling Tesla = Trump Admin not good. Sort of. Because the Republicans could just throw Elon under the bus at the end of the day, which some are saying has already happened - but it's the main point.
Falling sales in America, Europe and the world at large are thus seen as emblematic of countries and individuals rejecting the Trump administration. Chinese cars having higher sales in Europe (allegedly) is making news because it means America isn't winning in the electric car manufacturing space - again allegedly.
So yes had Charles bought a Tesla it would have been a major statement of many things. As it is, to the previous poster: Choosing not to buy a Tesla in preference of another electric car is actually now a political act by proxy. Major electrical stuff we buy and where it comes from is now political. The Chinese even bought fashion brands into the tussle with the expose on designer bags manufacturing. Companies are being told to keep their manufacturing in America. It's a soft war. That is why the OP is surprised Charles not choosing a Tesla isn't a bigger deal.
I like the fact that Charles bought a British owned car personally. But perhaps for US/UK relations he should have bought a Tesla. That would have gone down well with the current Administration.