Back in the day, Opels were sold via Buick dealers. The ‘67-‘68 Kadett featured a bullet proof 1.1 liter motor that after markets shops could hop up. The little engine would turn 7,000 rpm over and over. It was like a two stroke Kawasaki of the era.
Interesting you mentioned Buick handled Opel.
My local Buick dealer handled both Opel and MG so I had a chance to compare both rather easily. I kinda leaned to the rag top and went with the MG...and got to know the Service Manager on a first name basis.