[David]

Driving in Europe is usually a non-issue and Europeans drive MUCH better than Americans but we did just travel Italy by train when we were there a few years ago.

I've had best luck setting up rental cars with my company account with Enterprise/National. Much cheaper than Euro only brands. Also check if credit card provides rental car insurance in Europe. You may still need to provide proof of insurance but you won't have to pay for additional insurance.

Expect your car to be a manual tranny. Even if you request an automatic. I never cared either way but I've seen American's freak out when handed a manual car.