動車撞到非法停車，雙方都有疏忽，要看本州法律對共同疏忽的法律規定

1. Contributory negligence.  Victim cannot recover if victim is also negligent.  In the United States, the pure contributory negligence only applies in Alabama, Maryland, North Carolina, and Virginia, wikipedia. https://en.wikipedia.org/wiki/Contributory_negligence 

也就是說，動車撞非法停車，雙方都有疏忽，在pure contributory negligence states，（見上），雙方都無法向對方索賠。

2.  Comparative negligence.  Victim's compensation will be reduce by the percentage of his own negligence.  If a victim is 30% negligence, the compensation will be reduced by 30%.