I am having the same drama
I have an 11 year old who is obviously out of car seats ,my 3 year old is in a britax evolva 1,2,3 which fits fine.. my 6 year old is in a graco high back booster - this stops the seat belt recoiling . Newest advice is to keep children in high back boosters much longer hence why britax no longer make/sell booster cushions . Im also about to have our 4th child .
So I discover you cant use belted bases in the middle row of seats due to underfloor storage .. then I realise I wont fit a baby seat a high back booster and a britax evolva in the middle row of seats .. so my 6 year old in the boot is the best option but then apparently you cant use a car seat ?
To top it off Renault and mothercare advised me to get a britax high back booster for my 6 year old which came the other day and wont even sit in the car once the headrest is pulled up to the appropriate height for my 6 year old ... so we tested the 3 year olds britax with the headrest up and what a surprise that doesn't fit either at all ! So in a few months ill be in the same boat with my 3 year old ..
So my current situation is I don't have my 6 year old safely restrained in the graco -cant find another high back booster that fits ! I cant use a base in the back for my newborn , I cant use a car seat to have a child in the boot .. can put my 11 year old in the boot but then I cant fit../use 3 car seats across the middle ! So effectively a 7 seater only suitable for 3 children in car seats !
What a mess im in I don't have the time or finances to change my car , the advice ei get from halfords/britax/mothercare & Renault all contradicts itself and I just don't know what to do for the best ! the 6 year old could in theory go in a booster cushion but again this isn't recommended and ill have same issue with my 3 year old who I cant put in a booster
What a mess !