All of them. They're pretty boring shots, if I'm honest. Not much color or pop (you have to be aware of your lighting conditions) and the angle you took them at isn't very compelling. The biggest sin most people commit in taking pictures of cars is to simply whip the camera up to their face and snap. There's no thought for looking for an angle that makes the car look like anything more than a slide in someone's vacation reel. Generally, if the car is sitting in front of you and you take the shot from eye level, seldom will you get a good shot.
Trust me...I've taken PLENTY of bad pictures (and been given similar advice), so I'm not just trying to make you feel bad.
At the very least, you might want to take a shot at some post processing to warm them up and fix the composition. I'll take a couple minutes and see what I can come up with.