UNREAL UE4 - How to avoid AI from finding main character when it is inside vehicle?

HI, i need the AI to stop shooting to my main character as son as it gets inside the vehicle, but the line trace continues to find main character even if i change it´s object type as son as it gets inside the vehicle and i dont want to tick main character to update it´s object type because i want to avoid the tick to affect my game´s performance, since there is like 150 to 200 enemies, what else can i do?

Please help with BP images, thanks,

Here is my “Service BP” to find main character: