Patrice Bousquet wrote:
Car rental price are kind of similar to here. From Venice to the ring that will be a full day of driving an another one to comeback.
If you can fly to Frankfurt then you are 2 hrs away. Austria is nice so another itinerary might be: same start, leave Venice to Verona, drive around the Lago di Garda
Then north to Bolzano and Innsbruck, then to Salzburg ( Mozart place ) with a short stint on the German Autobahn. Then south to Zell am See, and the Grossglockner pass, you might see some car prototype there. This is a place where company go to test car. When we did it long time ago we saw some disguise cars. Then back to Venice.
Or for a little more driving. From Venice to Zell am See, passing by the Grossglockner pass, then Salzburg, then Vienna ( we did 2 days in Vienna, very nice, on that particular trip we did Austria ) and back to Venice.
I concur. The area around Lago di Garda is beautiful. Greece and Rome are not the same. Don't compare them to the Italians or you will end up a permanent visitor

If you do the northern route from Venice you could proceed from Lago di Garda to Milano or as Patrice said, go south and visit Maranello, Firenze, Roma. We did that trip minus Firenze. The Ferrari museum is awesome.
Alternatively, you could go up the coast. We rented a car and drove through Italy. It was exciting to say the least. The Italians have different rules of the road compared to the Germans.
Have Fun