All Fiat models could be driven in a sporting manner. They were raced and rallied with. 500's, 600's and 1100's in all kinds of variations. Before Fiat started participating with its own factory team, this was usually done by private individuals. A while ago I published a topic about an Italian car club that was rallying in a Fiat 850 Special. Now I found some photos of 850 Coupés that are being driven at full speed.
850 rally

Am I mistaken or did they taped the windshield back?

850 racingsportscars

I found these on

Fiat 850s also competed in rallies, in this case a Special. Zandonà-Bracco participated in the San Martino de Castrozza rally (apparently in the Dolomites) and were 14th overall. Quite an achievement when you look at the other participating cars.
850 rally 112