The interactions between cars and infected are not working properly. List below:
# Driving over infected (or any other AI) will not cause //any// damage to the car. This makes cars very easy to abuse as overpowered weapons against infected wherever it is possible to drive. The damage caused should depend on the speed and size of the AI hit (chickens no damage regardless - cows or bears catastrophic at speed). Different vehicles should be more or less resistant to this damage (think unmodified Sarka vs V3S or in the case of mods a reinforced Mad Maxish Mustang)
# Driving over infected will not cause a sound effect on impact. I think the sound effect works when running over players, but not infected or other AI.
# Infected will not attack players sitting in a car even if there is no door at their seat. Missing or open door, or an entirely broken window should make that seat available for infected to attack. Doors and windows should not merely be cosmetic.*
# Infected will often stay targeted on a car even if the players have left the car and are attacking the infected.
# Suggestion - Infected should pummel the door of a closed, unmoving car in which at least one player is sitting, until they break through the window and/or ruin the door, after which they should be able to strike the player. Cars should not be impregnable fortresses vs infected.
# Suggestion - after driving over infected the front and hood of the car should become stained with blood.
*) The flip side of this is that wolves and bears can and will attack players in a closed vehicle!