I like the concept of character's being able to see ghosts and their loved ones that died just so happen to "haunt" them and the character is the only person able to see them. I think it's fun.
So I'm imagining this with Lightning McQueen who is able to see ghosts. And after Doc dies he's still able to see him and vice versa. So it's almost as if he never died, except.....no one else can see or hear Doc.
So just imagine Lightning going about his day in Doc's house (would it be his own now?) and Doc is watching him inches away, simply floating in the air and giving commentary. Lightning sasses back at Doc and they go into a full blown witty banter argument when suddenly someone else enters. Maybe Mater? Or Sally? Either way, Lightning doesn't notice and is still bantering with Doc. Mater/Sally asks him who he's talking to and both heads whip over. Doc is having a field day watching as Lightning stammers and tries to explain himself.
On race days I imagine Doc would still coach him, headphones on and everything. Lightning wonders how he's able to hear Doc from so far away because he's not sure if the headset even works, but he doesn't question it. So just imagine the 95 crew's surprise when Lightning races like normal as if Doc were coaching him (which he is, but they don't know.) The two somehow have their own channel frequency. Lightning sometimes forgets and talks normally to the others and they're like ???
Anyway, in my little head I imagine Doc to die sometime after Cars 2 but before Cars 3 because yknow. Silly little angst. But his canonical death after Cars 1 works as well.
Anyway I love father son!!!!! Yay