Hi - just got a new car (Evoque) and am finding that with the current booster seat we have it's almost impossible to get the seatbelt buckled in ok. My daughter can't manage at all and I find it a struggle. It's an Isofix seat with back and arm rests. Can anyone recommend a similar style of booster seat that might be slightly narrower than standard and therefore easier? We also have a booster seat with no back rest that we use as a 'spare' and that is fine. But, from a safety aspect, I don't want to rely on it all the time. Thanks