There is a soft insulated container for batteries in Fieros that's available at the " Fiero Store " in Ct. . It's designed to help keep the heat away from a battery in the engine compartment of the Fiero similar to the 914's location/problem . Also , Cadillac has one available for use in its CTS models. These are soft walled containers with a lid that keep the heat away from the batter and absorb any battery acid that leaks.
So far the one in my '03 CTS hasn't given me any problem so t should work in the 914s .
It's worth a look at it to see if it's a possible solution to the battery leak problem that are in 914s.
GTPatrick