Interested in knowing how crowded the Sostas are as we see a lot of Italian MHs when travelling.
Like anywhere, it varies according to time of the year, proximity to popular places - in the summer round Lake Garda they are going to be busy, further afield less so.
Some sostas are free, some charge - much like French aires. It'll cost you the best part of €40 to stay on the Sosta at the end of the causeway in Venice but, it's in Venice, so what do you expect? Cheaper to drive round to the Lido de Jessolo, stay on one of the many campsites (several ACSI ones) and get the boat in.
Pleasant sosta at Soave, which is a lovely little town €6 including EHU. Nobody there when Google visited in April 2016!
Google Maps
Great free one at Orta san Giulio above lake Orta which (IMHO) is heaps better than Garda.
Amazing one at Oggebbio above Lake Maggiore, where each pitch has its own grassy terrace:
Google Maps it certainly wasn't busy when the Google streetcar came past in October 2016!
Very handy one in Verona - bit of a car park, but walking distance from the Amphitheatre etc.
Things to remember about travelling in Italy - it is worth paying the tolls for the motorway, they are nowhere near as expensive as the French peage plus many of service stations have service points where you can empty both grey and black.
Oh, and if you want a fab wildcamping spot, then avoid the Gottard tunnel and, instead, drive up and over the pass (only open in the summer) on the old road that winds round the lake:
Google Maps magical.
Morph