i don't think you need the blurry leaves in the bottom right and top left to create anymore DOF. there's enough already between the flowers in the foreground and the winding road.
Also, i think that the riders and car are just a distraction. you know what they are, but they're too small to see and and appreciate as the point of focus.
It's hard to see the riders in this shot, this is actually the first of about 5 shots from the same angle where the riders are eventually very visible, but I think I'm going to use this one because it'll likely be printed at around 8.5x11 for a calendar for my client.