The parking lots for visitors (€ 1.00/hour) are located on the roof of the exhibition center (floor +1), with an entrance on via Marco Polo Street. 
In addition, there are another approximately four hundred public parking spaces close to the exhibition center (via Buozzi Street or via Galvani Street).
 

Further information: http://www.fierabolzano.it/esp-arrivare-d.htm