We have a 1995 Chevrolet Corsica, (over 260,000 km) which is built using the
same platform as the Beretta.

The transmission cooling lines are made of metal and rubber.  Leaking
usually occurs where the rubber and metal are joined at the factory.  The
best solution is to replace the entire line(s).

We did have some near overheating situations with our Corsica.  The Radiator
Cooling Fan would not run, unless the Air Conditioner was on.  We found that
the heat sensor was not working correctly.  It is in the coolant outlet on
the 3.1 V6 engine.  You might want to make sure the fan does work, although
this failure is rare.  You may also want to check the fan relay.

About radiators:  The reason why they develop leaks is usually from bad
anti-freeze (coolant).  With time, the coolant becomes acidic, and the acid
action eats up the metal in the radiator core.
We have the "ph" (or acidity) of our engine coolant tested every year after
it is 3 or 4 years old.  As soon as it starts going acidic, it is changed
immediately.

Good luck,

David