Lets have some more information...

How many miles a year? Economy probably irrelevant if you are only doing say 4-5,000 miles each year.

Again, spec is also probably irrelevant if your mileage is low - how often will you spend in the car? 30 minutes each day? None of the extra features are going to be relevant apart from possibly air-con (even in winter).

How many kids and how old? Older kids may only need boosters, whereas younger have these increasingly large car seats so you can only fit two side by side.

The Jazz generally has the largest interior of any supermini, But width between internal door pulls is probably you main issue rather than overall space. Go and measure!

Also, higher cars are better for your back than lower ones.

The Kia Picanto is a much smaller car as is the Hyundai i10. You may be better off with the i20 or Kia Rio.

Well the most important question here is budget, without knowing what you can afford to spend, it is impossible to recommend something.

Couple of other points though, first of those being, there is no such a car as a 1.0 Honda Jazz. It is either a 1.2 or a 1.4, and that was the case from the very first of the 'modern' Jazz models ('01-'08), through next version ('08-'15), with the current shape changing to a 1.3, then adding a 1.5.

As for space, you have pretty much, through your own observations, ruled out a Jazz, a Yaris, or indeed, any other supermini sized car. The reason?, the Jazz is the most spacious car in its class, and while the version that came after yours, has a little more space, it wouldn't be a noticeable difference. So if it is currently "awful trying to get seat belts round the car seats for the 7 yr old", it is going to be the same with a newer Jazz or any other car in that class.

As i said, without a budget, i'm not sure how applicable any suggestions i made would bem, but reading between the lines, i'd guess your budget would be small?. So saying £1-2k, here are a couple of suggestions.

www.autotrader.co.uk/classified/advert/20190613897...1

www.autotrader.co.uk/classified/advert/20190610885...1

www.autotrader.co.uk/classified/advert/20190519812...1

www.autotrader.co.uk/classified/advert/20190613898...2

www.autotrader.co.uk/classified/advert/20190612894...2

Edited by badbusdriver on 16/06/2019 at 10:55