I’ll start with the Porsche 997, the 996 looked alright imo, but it looks “like a 90s Porsche”, the 997 made it look sleeker and more modern. Still looks good today.
As for cars that looked worse after a facelift? Maybe the facelifted 6th gen Camaro? The 6th gen looked great pre-facelift, but they did something weird with the headlights and now it looks so-so…
Here’s one nobody gives a shit about:
Chrysler Pacifica (the current van, not the old crossover)
The nose alone is so much worse. The taillights are actually better, but God is the nose awful. It used to at least look vaguely elegant.