I’m getting a high back booster seat for our second car, for my 5 year old, 43 lb 45 inch daughter. It will be just for quick trips in dads car- she is harnessed in our britax frontier in my car.

1- is there an inexpensive ($75 or less) harness to booster seat that is easy to install and narrow? Having a harness would be nice since then little sis can also use it in a pinch, but I’m thinking unless it’s super easy to install, it’s not worth it. We already have two big, expensive, car seats in my car, which is where the kids ride 95% of the time.

2) assuming we go the high back booster route, recommendations for one that is narrow (so a smallish person could fit in the backseat along with the car seats), has Latch connectors so it isn’t a projectile and doesn’t shift around, and is fairly easy to move around or travel with in the future? I’m leaning towards the Graco Affix high back booster, but open to other ideas. Both kids are pretty short so I’m not worried about a high height limit.