Lots of investment in classic cars still - though I wasn't aware values were that strong.
I collect old Japanese hi-fi (70's and 80's era) and the market is really strong now on e.g. eBay with Japanese collectors buying the best quality classic Japanese products "back" from abroad. Is the same thing happening with the cars too, and fuelling values?
I think it's more likely our European friends will buy from the UK rather than from the USA, but there's still a very strong following in this part of the world. I got an agreed value from my insurer on my R34 of £100K last week, if they think they're worth that then it's probably an indication values are climbing (they do know the work I've done on it and that it's like a new car though tbf).