Strange modded police car damage issue?

I have a problem have had for a while in my modding of the game where if i run into wall hard or blow up police car it will spawn another or a few copies of the blown up model instantly? it seems to affect sheriff, sheriff2, police4 from what i could tell? Is there a resolution to this? in the picture attached you can see many damaged models spawned after rpging the sheriff2. they dont have physics really either and i can walk through them. police1 police2 and few others seemed unaffected.