I live about an hour from Bologna. You won't find a lot of free parking and it's likely to be more than the 10 euro per day. How long will you be in Bologna? The old town is pretty compact, but interesting and there are several museums including the archaeological museum that are worth visiting. The Bologna Jazz Festival starts on the 7th.
http://www.festivaljazzbologna.it/ If you've got a car, you might be interested in going to the Ferrari museum south of Modena:
http://www.galleria.ferrari.com/Galleria… or to an acetaio in the area for a tour and balsamic vinegar tasting:
http://www.balsamico.it/ or visit a caseificio where parmigiano reggiano is made:
http://www.parmigianoreggianocastellazzo… There's a horse show at the fair grounds in Verona.