I have 2 high back boosters for 2dd aged 6. One dd is travel sick and I would like to put her in the middle of the back seat so she has a better view. The 2 high backs are too wide so I have been looking for a narrow ordinary booster with a seat belt guide strap - no luck! I have 2 choices, either a booster with no guides in the back or put her in the passenger seat (no airbag). I've never let them travel in the front before. What does everyone think?