What does the above images tell you about the amount of blood spilled in the rear seat of the limo? We can't see the lower front of the shirt but one might assume that the collar area was the most photogenic. Had there been more blood lower down then the photo of the front would have been similar to the back of the shirt seen in the second image. Neither of these images can be automatically accepted as genuine although the FBI label increases the likelihood this image is genuine. There would be no reason for making two rips just below the collar because this does not fit any of the messy forensics and does not even point to bullet holes at all.
The other side of the shirt does show blood seepage on the left side. The blood has soaked into the shirt and has ran downwards. Jack was sitting up when this happened. It also shows the extent of the blood seepage. Jack's back would have been against the back of the rear seat and would have unlikely spilled off the front of the seat down the verticle front of the seat and onto the floor. The amount of blood on the back of the shirt is out of proportion to the blood on the rear seat and what the amount that has trickled down onto the floor. The shirt shows no sign of any blood staining whilst Jack was laying along the rear seat. The staining on the back of the shirt only happened when Jack was sitting upright.