[dicklague]

My 1979 Saab turbo had awful air that was broken more than it worked. The mounting bracket would break, the idler pulley bracket would break. The hoses leaked.

The 1988 turbo convertible air worked well with little maintenance. My 2001 95 Aero has worked for 13 years with one less than $100 gas top up. My wife's 2003 Aero Saab A/C has never been touched and works great.

I think it is just development and refinement and better tech.

In the 70s and 80s, the Euros did not know why us Yanks wanted air conditioning? They did build systems, but they did not have a ton of development. The Porsche was a tough problem with no air inlet grilles in front and engine in rear.