I'm looking into purchasing a booster for DD who is 6 years old. I got recommendations here for the Graco Affix and Turbobooster LX. Both looks great and I was going to pull the trigger on the Affix but then I wonder if I should look into a more narrow option. We drive a minivan and ideally would like to have 3 across in the back row some day when the kids are older. Right now DD2 is 3 years old and DS is 1. Do you know if the Affix or Turbobooster is narrow enough to fit 3 across or is there a better option? TIA!