As a British American
What is a British American??
out of the 100 I looked at, 99 were US salvages.
That's odd, unless you were looking for American cars - or something with an enormous engine. If you just search for a European or Japanese make of car you'll find that a lot of them are imported from other European countries, not from the US. In fairness, the used car market is pretty dodgy but it's not as bad as you think.
I've also used Allegro for dozens, if not a couple of hundred purchases and I only had a problem with them once.
I wouldn't say that medical services are scammers but they're not as professional as one would hope for. I once had to have a visual fields test at LuxMed and I thought the girl performing it seemed a bit inept. I engaged her in casual conversation (that in itself is a feat in Poland) and managed to find out that she'd had very little training in using the equipment and that her last job was as a dental hygienist. I'd expect a nurse or properly trained technician to be carrying out such an important test.
But, Poles are definitely not all thieves and liars. They're a mixed bag. They're not the 'nicest' people but not the worst either. Poland is a lottery, and your chances are absolutely fifty-fifty down the middle as to what kind of experience you have in any given situation. It can be just fine or a shambles. Are you still in Poland?