Thanks...I actually do know all this.

My 11 year old remained in a booster until he was 4'9" (which was last year, long after almost everyone he knew was out of a booster); we didn't take him out until he was tall enough and the seatbelt fit him properly. My 8 year old is in one at home--a backless one with me, and a high back in DH's car. I'm honestly not even sure what the law is here, but I know it's not very strict. The only reason I was considering not bringing it is because of the fact that we are not going to be driving much at all; while I know accidents can happen at any time, he does meet the legal requirement. I do appreciate your help, though. Now, back to vacation planning!