Could I throw another GM product into the mix
Opel Calibra 1989-1997 - cd of 0.26 in 8v form (the 16v, turbo and V6s were worse).
Prior to this the Kadett E (aka Vauxhall Astra, Pontiac Le Mans, Daewoo all sorts) was also designed with aero in mind, including mostly having flat wheel covers skinny (i.e. Michelin X) tyres.
I remember reading a motoring journo long term review in the 80s and he praised the 1.3 litre Astra for being able to cruise at 100+ with 3 passangers. The 16v 160hp version was claimed to be capable of 150mph - although in reality it struggled to that. This was in 1985.
And prior to this (we are in the 70s now) the Mk1 Vauxhall Cavalier was also aero styled for the time - flat wheel covers, sloped lights and so on. And this came after the Vauxhall "droop snoot" phase.
Droop snoot goodness here :
Vauxhall Magnum - Wikipedia, the free encyclopedia