After WW2 Volkswagen didn't change their name or Nazi branding (if you haven't seen the uncropped version of the VW logo you're in for a surprise) exactly because people in Allied countries refused to buy German cars after the war. Even if VW or BMW or Mercedes had rebranded and apologized it would have made no difference. Their ties with Nazi leadership was too strong for any apology to be credible. What Frenchman would buy a Nazi car over a French car in 1950s? And so the German car companies focused on domestic sales, which meant they had to appeal to humiliated (former) Nazis for sales for which any rebranding would have been a negative.

German car companies absolutely were boycotted after WW2 in much of Europe (and rightly so) and boycotting Tesla for Musk's antics is consistent with that.

At least some people are probably putting "I hate Elon" stickers on because assholes are out there destroying people's cars because they have beef with Elon, and they don't want said assholes to destroy their car. It's lamentable that people are willing to act so poorly that they think it's OK to destroy innocent parties' property as a form of protest, but so it goes.

Because there are a lot of folks out there who think that merely patronizing a business supports everything their leadership stands for

I needed to replace the 12v battery in our Tesla a few months back, and was surprised to see a protest out front. I laughed to myself, glad I had driven my Porsche to the service center instead.

Thankfully, I said to myself, none of our non-Tesla cars have problematic histories.

(Mussolini, Hitler...)