Yes indeedy-do! If you don't get the old failed part back, how can you demonstrate that it's been replaced? Get your car fixed, and you can demand the old parts back, at least in California.

Again, for most people, how much would knowing these things change behaviour?

I gotta say, man, Planesdragon speaks truth. No matter how else we may f**k up, you just can't beat that 1st amendment, and I've never heard of another place which has anything like it. I can stand on the street corner and shout as long as I want that Muslims and queers and cops stink, and several decent people may wait in line to beat the crap out of me, but I have nothing to fear from the state. Even as a visitor, you would have the same freedom. Of course, there's a constant struggle between those who value that freedom and those, some very powerful, who , for their own benighted reasons, seek to suborn and disfigure it. But that happens everywhere. Three hundred years isn't a long time, compared to how long the UK has been there, but every time there's been a serious threat to that right, and there have been several, Americans have risen to reaffirm it. For that reason alone, I would say the US would be your best bet. And most people here would agree. Just sayin'.