We could recognize it by the sound of the engine (maybe). However, the car’s sound wasn’t heard much in the anime, so we don’t really know how it sounds like to know which engine is it using. We know how this car sounds like in real life, and also we know it’s original engine, but it officially comes with two (2) engines; V8 and W12. I’m sure the Continental GT originally uses the 12-cylinder engine. Although for Kambe’s Continental GT, either it’s a V8 or W12.
https://preview.redd.it/y57xflpzzwfa1.png?width=882&format=png&auto=webp&v=enabled&s=cf4b81fb18502cd215db323282930dc96ee95338