Interestingly, back when these cars were new I was working with an American guy who came over here regularly. I took delivery of a brand new Omega whilst he was over here and a rather intersting arguement started ........
Seems his mother had a Catera and he insisted that the Omega was made by Cadillac in the US and shipped over here to be sold. I, of course, insisted otherwise and proved it to him easily enough as there is a "made in Germany" badge somewhere on it. He was "gobsmacked"

It seems that the Catera was marketed specifically at the "blue rinse" generation in the US in the same way that the Lexus IS300 was targeted at school kids who would get Daddy to buy one new for them on their 16th birthday

. If that is the case I can see why you would get low milers some up from time to time.
I've just been to my local dealers & bought a whole bunch of parts to fix my leaky exhaust manifold gasket. I also got a complete set of filters (oil, air, pollen and fuel) and the bill for the whole lot came to 80 pounds - which is about 120US. I'd certainly be happy to ship parts over as I'm sure others would be.
BTW - fuel here is a lot more expensive than yours

. I filled up today and 65 litres was 87 pounds - that's about 130 USD

. That's about the only downside of running one of these & my many of the guys on here have converted their cars so they can also run on gas as well as petrol. I have't personally, but there are a lot who have.
All the best