Britax Evolva Plus - for 1.5 and 3.5 yr olds?

[ConfusedKiwi]

We are coming back to UK for a long visit next year, boys will be approximately 3.5 and 1.5. In-laws have very kindly offered to purchase car seats (which we intend to take back to NZ with us as they are mega expensive here and have been hiring from plunket for grandma's car for now).

Looking at Britax Evolva 123 Plus (although I'm not clear on difference between this and the non-plus?). Does anyone have much experience with them? They are $400 to buy over here and no-one stocking them locally. Both boys are tall for ages (95 - 105% on height charts).

FIL keen to buy now since sales on at Mothercare and Halfords.

[JellyTopicecreamisthebest]

You need to know the kids weights. The harness only goes up to 18kg and if they are tall they may not fit it the harness. They also need a lot of seat belt to fit and can be difficult to get them tight in the car. I am in NZ moved here 6mths ago so know about expensive seats. It is probably a seat that you need to try in you car here (nz) Do you have issofix If you do I would look at the Xtentsafix I have never seen the seat but the harness lasts longer. You don't have to put it in with issofix

[ConfusedKiwi]

Thanks, problem is I would be guessing on weight and height since not travelling until May 2014 but being pressured to make a decision so they can buy now.

Will look at Xtentasfix - we have isofix car here and in car we will be using in UK. Thanks.