Cosatto Port 0+ car seat - safety & compatibility concerns?

[ThePartyArtist]

After a lot of research into travel systems we are fairly set on the Cosatto Wow. You can buy a car seat to go with it (Port 0+). However I have a few concerns and wondered if anyone else has experience of this:

1. My first question is about whether the Port 0+ car seat has a harness that can be undone by a child of the age that'd be using this seat?
   
   The manual says 'The harness buckle has been designed to be released quickly in an emergency. It is not childproof. More inquisitive children may learn to undo the buckle. Children should be told never to play with the harness buckle'.
   
   When I asked customer services about this, they told me; 'The harness is not child proof. This does not mean that a baby will be able to undo it, however the button has a quick release mechanism (in cases of emergencies) so it needs to be easy to find, easy to press and it needs to be able to be released by anyone regardless of age and physical abilities. This statement is more relevant in our Group 1,2,3 car seats as a toddler probably would be able to undo the button.'
   
   
2. My second question is - how likely is it that this seat would fit a wide range of taxis / hire cars / friends' cars? Has anyone had experience of this?
   
   I have heard of people buying car seats then finding they're not compatible with their cars - we don't currently own a car but we need a car seat that is compatible with a wide range of cars, for when we're getting a taxi / going in a friend's car / hiring a car / buying one eventually.
   
   Cosatto can't provide me with a list of cars the Port is compatible with - they say it is sold separately from the Isofix base and therefore a compatibility list isn't available. I think in reality we'd more often use it with a seatbelt. They tell me 'The port without base is classed as a universal fit, meaning it should fit most, but not all vehicles with a standard three point vehicle seat belt. We can't guarantee it will fit all vehicles though as all vehicles have different seat shapes etc.'

[moggle]

I don't have experience of the Port but my thoughts are

1. No child car seat can be said to have 100% childproof buckles, I doubt the Port is any different. As they say, this isn't really relevant to a group 0+ seat as even at the top end of the age in this seat they do not usually have the dexterity, strength or cause and effect intelligence to be able to or to want to press the button. My daughter is in a group 1-2 seat now and I think at 26 months in theory she could undo the button on her harness but she has not yet.
   
   
2. Most of the group 0+ seats do have a near-universal fit. No company is going to say they will fit in every single car as they have not tested them all, but group 0+ seats are quite small and so the usual problems you get with fitting bigger seats (seatbelts not going round the seat, seat slope causing recline problems, seat not giving enough room between childs face and back of front seat) are not an issue with these seats. I don't think any group 0+ seat will cause you problems fitting in a wide range of cars. Having said that eg if you buy a Maxi cosi cabriofix they have a fit checking thingy on their website so you could check for a particular car model; however, with the cabriofix I think the purpose of that is more to tell you which seats the car seat can be fitted into (eg middle back seat, front seat cannot be used in all cars).
   
   I would also be looking at checking the seat has passed the relevant safety legislation and also how big the seat is as some of these seats have a shorter back than others, meaning they grow out of them faster. Also I would be looking at lie-flat seats, however if you don't have a car and would generally be only making short trips this probably would not be such a big deal.