93 BMW 318is,coolant leaking from tranny bellhousing

Anyone know how or why the coolant gets to the tranny area? Most vehicles cool the ATF via a separate area in the radiator or a separate radiator. Does not seem to be leaking into the oil via a blown head gasket or manifold gasket? Absolutely no help from Bentley’s, Mitchels on Demand, or Mitchell’s. Any suggestions, car belongs to a student with Dx of MS and we have very limited funds. Car was donated to him, he nor I bought it. Thought these German cars were immortal?

Head gasket leak at the rear of the engine, intake manifold gasket leak at the rear of the engine, coolant hose leak at the rear of the engine, leaking freeze plug at the rear of the head or block.

There could be a freeze plug INSIDE the bellhousing also, depending on the block design…