Well, I did some research on the car seat issue. It turns out that Italy, France, Spain and UK have similar car seat rules to the US. For 4 and up a booster seat seems to be acceptable (they call it a raising seat.) The booster allows the child to have the shoulder strap (when available) placed in a safe place across their chest. Children under 12 must ride in the back seat of cars. Many regions are enforcing seat belt laws and car seat laws because of the amount of traffic accident deaths.
We only have one child and waited until we were old enough to not have any more, so we don't want to injure or lose her to something that was a little inconvient. So, even though we don't want to lug one more thing around, we're going to bring the small graco booster seat - unless someone else has another idea -
I'd love to know what else is available??? In California, we have pretty strict laws about car seats so we are still in the big car seat currently. On the buses we can leave it onboard while touring.
We don't use a stroller very often anymore, but thought it would be a good idea to find a collapsable or folding umbrella stroller that we could attach the booster seat to it if needed while traveling.
Does anyone have a stroller they would recommend to fit a just turned 4 year old?
Something that has worked great for us at
Disneyland is to attach 2 or more large caribiner clamps onto the handles and hang anything off of them. Keeping in mind the weight of your child so you don't tip your child backwards!
As far as the airplanes are concerned, my SIL is a flight attendant and they tell everyone that your child should be tall enough to have the backs of their knees reach the end of the seat for the seat belt to be a good fit. Otherwise use a car seat because it is the safest for air pockets.
When we arrive in Florida, we have to get back and forth from the port and WDW and the Florida law is that over 4 uses a booster seat as well.
So, that is the information I've found... We know too many people who have lost their children to accidents, so we'll view the booster seat as important as our passports. If anyone has ideas, do let all of us know.