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…
This is controversial but the G30 generation of the BMW 5 series went through a nice facelift imo (new headlights, tail lights, grille and bigger infotainment screen) although many did not like the new headlights
The facelift of the G30 5er is one of my favorite “realistic” dream cars