I made a hot air balloon, where the basket is the actual vehicle and the balloon part is a separate part you attach.

I tried to see what happens if you shoot it down, but found out that apparently it does nothing. You have to hit the core part of a vehicle to shoot it down. This is unfortunately, because realistically, if you shoot the balloon part of a hot air balloon, it will go down. There should be some sort of setting that allows a part to transfer damage to the core part.

Hi there! If you would like a part to forward its damage to the vehicle, simply define forwardsDamage in the generic section of the JSON as true.

It appears this wasn't listed on the wiki, I'll get on that to ensure no further confusion arises from this! (Because apparently we have forwardsDamageMultiplier on there, just not the actual forwarding parameter.)

Ah, amazing to see that this is already a thing! Thank you for telling me about this. And yeah, probably best to edit the wiki to include that value.