Question RAV4 with 2 Car Seats in the Back plus an adult

We have a 2005 RAV4. The middle seat in the back has an over the shoulder belt that comes down from the ceiling, clicks in to a seat belt anchor, and then acts like a normal over the shoulder belt.

We have two children. Right now our youngest at 8 months weighs about 16 pounds. Our oldest is almost 3 years and weighs about 26 pounds. Right now we own a graco snugride, graco snugride 32, and graco myride 65. Our oldest just recently outgrew the snugride 32 in height. Both our girls are petite.

I would like to fit two car seats in the back of the RAV4 side-by-side, so an adult can also sit in the back behind the driver seat. I plan on having the snugride/snugride32 in the back and buying another convertible. I would also like to use this convertible for airplane travel and in car rentals. While traveling, I would like to be able to fit the car seats side-by-side in a ford escort. This convertible car seat will be used occasionally for travel and errands at home. What would you recommend?

It would be great if it is possible to find a seat that will fit. From what I've read so far, it looks like I should try the sunshine radian. Our other car is a 2009 Toyota Sienna just FYI.

Yours is before the change in design that made 2 of the seatbelts overlap, right? (I'm thinking that was 2006.) If so that middle seat is VERY narrow and yes, I believe the Radian is a good choice for that spot. I have put rear-facing Radians in the center of similar model year RAV4s, though it was difficult. The MyRide might "puzzle" well over the Radian (you'd need to check for independent install of each seat.) That would be the first thing I'd try. Otherwise you MIGHT be able to fit an infant seat next to the Radian, though it's hard to say.

Are there any other less expensive options or possibilities?

Well, there are lots of less expensive seats, but most are significantly wider, and you're working with a very small space.