Unfortunately this thread looks like it may become a shouting match at each other. I'd like to attempt to diffuse that and add in some logical thought here. Please review below.
Car Accidents Caused by Negligence | Nolo.com
Key provisions to read for the defendant, in this case, the Z driver. "Duty of reasonable care" and "breaching". Also take special note of "reasonable person" definition.
One of the questions we need to ask ourselves is, would a "reasonable person" drive 65+ mph on a 35 mph road, with many side streets, weave through traffic and talk on their cell phone at the same time. I know I would not and I'm guessing 90% plus on this forum would not as well.
Now lets address the claim that the van did not stop properly, please remember that the van and the car to the right of it entered that intersection at the same time. Both of them were not expecting a car to be weaving and speeding at 65 mph+ on that street. IMO that's evidence that would lean heavily in the favor of the van driver and the car turning right acted in a reasonable manner. Much more so than an individual speeding, weaving, cell phone talking driver.