yes it likely just spills out into the engine compartment, but it is good to have some cooling in there. Under hood temps are a key factor in how long electric components last.
As for the battery enclosure, the designers must have decided that it needed shielding from the under hood temps, that's why they put it in an enclosure. Heat kills batteries (speeds up the chemical break down process) this is not a big deal with lead acid
batteries but it still is a factor.
Can you post some pictures of the current set up and of you planed mods (tape some cardboard up)?
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