At first glance, PSG are a fresh-off-the-lot Ferrari. Peel away the sparkling chassis and glistening paint, however, and there are serious engineering flaws that could prevent their Champions League charge. Again.
At times against Juventus, the most expensively-assembled front-three in history were completely unplayable, and Mbappe's quick-fire brace, helped by Neymar, showed the special, glistening side of the French club.
Yet, defensively they never looked entirely comfortable, with Filip Kostic and Juan Cuadrado causing trouble with their pinpoint deliveries into the box. Once Weston McKennie cut into their lead, their mental approach seemed to disintegrate in a scary reminder of what happened against Real Madrid last March.
New boss Christophe Galtier still has work to do to prove the same old problems that have prevented the club lifting the trophy can be addressed.
But it helps he has Mbappe on his side. That's a head start over almost anyone on the continent.