Punto 188 1.2 16V no longer starts

Today I have to bother you with a problem. The Punto 1.2 16V of my wife (year 2002, almost 60.000km) has not started any more. Yesterday (at -15°) the starter worried disheartened, but the engine did not jump on. Although the battery is new (about 3 weeks old), I then got it with starting support cable. In the afternoon after work the car started without any problems. This morning (-17°) the starter ordered even weaker (with no breakdown of the on-board voltage with clock extinguishing e tc. as in the case of a weak battery), did itself with every turn heavier and then did not turn at all. With starting aid the same, first some revolutions, then nothing at all. All cockpit lights or the interior lighting shine strongly and do not become darker during the start attempt. The CODE lamp extinguishes after a short time, so I close the immobilizer already. My wife does not drive a short distance, but about 60km per route highway to work. I have to i attached starting aid cable measured the voltage at the Punto, it was 14V on (donor car ran). Today in the day my wife tried to start again several times (hoping for a miracle). At first nothing was done at the starter. In the third attempt in the afternoon a bright electric motor buzzing suddenly sounded from the front, as if the starter is no longer coupled. A friend (Fiat-Mech.), whom I described the problem by telephone, said it sometimes there were problems with freezing condensation water in the tail muffler at Punto. Can it be that despite the long driving distance (but currently at low speed due to the rhinestones conditions) the condensation water in the end pot does not evaporate, because it is just so cold outside? And thus everything freezes at night? That would possibly explain the ever heavier turning of the starter, or ? Or does someone find another possibility ? sst a frozen interlinking suspect, or ? Or during the organ tests what is burned?? Unfortunately the starter is terribly installed in the car, you can almost not get without stage …