First, I am a car guy. I think that there are few things more wonderful than driving on the open autobahn or autostrada. If you want the ultimate memory, take a drive down the Strada della Dolomiti - just incredible. My wife and I tallied things up earlier this year and figure that together we have driven over 200,000 miles in Europe over the past almost 25 years. I tell you that so that you can see that I have a very strong bias towards cars in Europe and you can take that into account with my opinion.

I basically agree with what Zooropa said. If you want to get into the weeds in Italy (or anywhere else for that matter) and maximize your time, you've gotta get a car. There is no way to do the same trip by train without making your trip 2-3x longer and just deciding not to go to some places. A car = flexibility.

You should be aware of a few things though:

- Gas ain't cheap. Right now in Germany, gas is just shy of $10/gallon; so in Italy, it will probably be similar. However, cars here tend to be more economical than in the US.

- You have to plan ahead when you are going to park. In the countryside, not so much, but in the cities, definitely. And in Italian cities, you typically can't drive into the centrum unless you are a local, a taxi, or are staying at a hotel in the centrum. If you do, they have cameras and will fine you. However, people who complain about the difficulty of parking in Europe, just don't know what they're doing. Yes, at times you may end up a little further out in a parking garage, but they almost always have quick bus or tram connections right into the centrum. For example, Venice has huge parking lots within easy walking distance of Piazzale Roma. And yes, I do have a three-inch scratch in my mirror from a very narrow alley in Orvieto and another from a tight corner in Siena. I just see them as great memories!

- Finally, in Italy you have to be a bit careful with cars. They are targets for theft, even in gas station parking lots. We typically dropped off our luggage at our hotel when possible and then continued on exploring with an empty car. Sometimes that's not possible, and you just have to be smart about where you park. Most people will be just fine, but it is a consideration, and please don't use your car as a safe deposit box. Everything you really need, phone, cash, passport, etc. should go with you when you leave the vehicle because the typical MO, is a smash and grab and then take everything a few blocks away and rifle it for valuables.

- In Italy, the tolls are expensive, and in Switzerland I think the vignette you have to put on your window is about $40 regardless of how many days you'll be there because it's a year pass. Sometimes you'll get lucky and a rental car will already have a current vignette on it. Austria is a bit cheaper, because you can buy a 10-day motorway vignette for about $10.

If all of that sounds like too much, and you decide the train is for you, then that's fine. Kids tend to love the train. But you do need to plan your trip around your trains, which was kinda tough with little kids the handful of times I did it. And there really aren't any trains that provide regular service into a lot of the small valleys in Tirol and Sud Tirol - those are mostly buses. When we have taken the train, we usually pack sandwiches and drinks, as I don't care for the train food, and it's pricey.

So, really long answer, but I hope it gives you an idea about what would be best for you and your family.