I think that before everybody starts getting their knickers all up in a bunch over these pictures of the "Jokermobile" they should take a step back, take a deep breath, and calm down. We're seeing only a couple of pictures, with no context, and jumping to conclusions over them. We don't know for certain that this is actually Joker's car and not just something he stole or borrowed. We know next to nothing about this iteration of the Joker and what he's like, for all we know this car might be very fitting for this particular version of the Joker, or maybe it fits with the overall tone and feel of the movie.
Now, I'm not trying to defend this film, I'm just saying that we shouldn't pre-judge it based solely on few pics shown out of context. This film may turn out to be utter crap, or it might be DC's Avengers of GotG, either way it's too early to tell and to get all worked up over.