You can do it in multiple ways, it depends on where you want to have that logic.
In general this should work, although this only works with 1 Car if you want to to work with multiple cars you’d have to do some extra logic and checks in the TriggerBoxBP.
TriggerBoxBP: Screenshot - 42a6f4d0d84a81df6d62b1cd68218203 - Gyazo
CarBP: Screenshot - 370af5a38895b90de2175d6b99859baa - Gyazo
Not sure if this would work in instances where the car is already in the box but is damaged. But this should put you in the right direction.