Just got back from two weeks in Italy; rented a "large" car from Hertz to carry 5 people and shopping results from the Prada and Gucci outlets in Tuscany. The large car turned out to be a Silver C220 Diesel wagon! Here's a few observations....
I thought my C240 was "sedate" in acceleration, but the C220 is almost boring. However, it did not complain going 200 KPH (120 mph) on the autostrada for long periods. When we got off the aotostrada and into the Tuscany hills (really winding roads), the low-end torque of the diesel was great! Even though it was an automatic transmission, I used the "flip left to downshift, right to upshift" mode to get engine braking for turns and had a good time negotiating the hills and turns (don't see many of those in Florida!) The car had a cloth interior similar to the coupe in the US. The radio had a casette, but it was on top of the display rather than behind the flip-down display in US cars. It had a single cupholder, but did not have the pop-up cupholder for the passenger. Even driving enthusiastically, we got great mileage (I have not figured out what it was in mpg since you buy fuel by the liter). This is important since diesel is about $3.50 per gal, and gas is over $4.00 per gal in Italy.
All in all, it was a great treat to get the Mercedes even if it did cost about $88 per day with all the insurance, etc. I'm glad I didn't get an Opel Astra or Renault....

Sounds like you had a fun adventure! I was in Italy last Sep/Oct and traveled around the same roads.. Milan, Venice, Florence..... We actually drove down from Germany. I had reserved a MB in Germany, but Avis does not rent MBs if you are going to drive them into Italy (something about a higher theft rate). Ended up renting a Volvo wagon which was actually quite roomy and nice. Looking forward to my next trip there.

Interesting you mentioned theft....I max'ed all the insurance, and could not get a "no deductable" theft. Had the car been stolen, I would pay about $1400. I borrowed an Italian "Club" device which attaches the steering wheel to the brake pedal and felt pretty secure. While I was in Rome, I could park the car in a locked garage area unless I was out eating or something.
My daughter is marrying an Italian citizen who grew up in Rome next June, so part of the trip was selecting a church and reception venue in Rome. It is a fantastic historical city and my daughter will be married in a church built in the 4th century.
However, in Rome, the drivers make 3 or 4 lanes out of a two lane road, and the hundreds of motor scooters constantly weaving in and out scare me a little.

Before you go again and rent another car, you should check with your Credit Card company about insurance coverage. I normally use a Platinum Visa/MC which will cover collision on car rentals overseas as the primary coverage (in the US it's a secondary coverage meaning your own insurance will pay first). I never take any additional insurance.

I know what you mean about the scooter situation. We didn't get down to Rome on this last trip, but driving in downtown Milan and Florence during rush hour was intense!

Best of luck for your daughters wedding! Sounds like it will make quite a memory!

I went to Rome last november and had plans on renting a car to drive around and see the surrondings. Seeing all the traffic and on top of that all the attitude most of the roman drives showed, it din't take long 'til I changed my mind... Busses and subways worked just fine. I was so impressed by the bus drivers

Magnificent city!