What is the narrowest backless car booster seat available?

What's a good car booster seat for a 2 1/2 yr old that converts to a straight booster seat?

• We need one that will adjust enough to allow the child to sleep without her head rolling all around. She looks so uncomfortable in the one she has now and she is close to 40 lbs. so she can move up to the bigger car seats that convert to a backless booster seat. I've read so many reviews that say certain ones are horrible to sleep in.... so what's a good one?

• Answer:

  First - your daughter is probably already too big for her current seat - her shoulders MUST be below the harness forward facing... if her shoulders are above the top harness hole, you need her out ASAP. Second - There is only one seat on the market that currently converts to a backless booster that is also a higher weight harnessing seat. Do NOT put here in a highback booster... she is too young. You need to purchase a harnessing seat. The only harnessing seat that does this is the Graco Nautilus. Some other options are the Britax Frontier, and the new Evenflo Generations 65 (don't get the old one... that only goes to 40lbs). But- in general, these harnessing booster style seats are more upright - and that's because boosters really require the child to sit upright for the belt to fit them correctly. I would pick the graco nautilus or the Evenflo Generations 65... you can try them both at babies r us... (and you can trade in your old seat right now for a 20% off coupon). Make sure she has some room above her shoulders for growth.