It's not a bug. It's a side effect of the way we do AA on PS4, and is arguably a good thing (hear me out!). It's there, and very noticeable from static images of non-direct feed footage especially, but also undeniably in the game itself (mainly when paused). I spotted it and reported it as soon as it got checked in long ago (so we didn't "miss it" as many would have you believe).
However, I also "spotted" that the PS4 version has really lovely image quality, a very smooth and slightly soft (not low res!), "non-gamey" look, which is very natural, and (imo!) rather fantastic, due to this very clever AA approach. It also greatly minimises the distant "shimmer" you often see in console racing games, which is a side effect of low quality AA on thin vertical objects such as fences.
So yes, the ghosting effect is there, if you look hard enough. The advantages far outweigh this small disadvantage however. Notwithstanding that, if customer feedback demands it, we have a plan to add a UI slider in a future update, which will enable you to tune out the ghosting, at the expense of more aliasing and distant shimmer.