traveling... car seat dilema

[saritasmile]

So in a week i am going to visit my parent. we are flying. this will be my first trip alone w/ 2 kids.

Ds, who is 4, is in a britax regent and dd is in a roundabout. i don't really think taking the regent is possible since it is so huge and may not fit in my parents car. I really don't want ds to be in a booster seat but don't know if he will still fit in the roundabout. so i guess the dilema is: do i put him in the roundabout even tho it's probably too small, or in a booster w/ seat belt? ( i have a bucket i can bring for dd) honestly, i'm terrified of using a booster w/ seat belt but will if it's safer than the roundabout.

if there is some option i don't see, please point it out!! :

[4evermom]

For starters, see if ds fits in the roundabout so you know if that is even an option. The round part on the back of his head should not be higher than the back of the headrest. The shoulder straps should be at the same height or a little higher than his shoulders.

You don't want him in a too small car seat because he will get a wicked case of whiplash if there is no headrest behind his head. If the straps don't fit right, it will allow him to move too much during an accident as well.