Transfer NBT values and inventory between entities

So basicly its the same thing as replacing a block and keeping NBT/inventory values but for entities which would allow to change an entity for another "state" while keeping inventory in the GUI

For exemple, im trying to make a custom car that can only be drivable if fuel is in the GUI BUT if the non-drivable version of the car get change for the drivable version it loose all the fuel and trunk capacity. This is also problematic because I cannot set the enitity health level so the car keep the same amount of damage it had before.