The 1965 Chevrolet Impala shown here waits outside Frederiksborg castle, Hillerød, Denmark. From a distance the style suggested an Opel Admiral.
As I got closer the florid Chevrolet script corrected my misapprehension. The driver filled me in on the year. This is another GM car to add to the network of influences cross-crissing and cut-jumping between Germany and the US. Up to now my idea has been to compare Opels and Buicks.
The Impala adds another strand to the weave. Were these similarities as clear then as they are now? Does the period where Saturn and then Buick took Opel platforms provide a recent parallel? And it is only parallel – the distance varies depending on how much of the Opel body Saturn and Buick got to mess with. In the 1960s Buick and Opel and Chevrolet might only have shared stylists.
This reminds me that I will be preparing an item on Opel in America soon.
Driven To Write 
I hope you will include the Buick Opel, which was nothing of the sort.
Somewhere in my archive there’s a copy of Road and Track with a GM advertorial “comparison test” which concludes that the Japanese Opel is nearly as good as the VW Rabbit. Such was the way in these days.