Car hire with kids from barcelona airport

[scooters]

Hi all, I'm after a bit of help from the PH fraternity please.
We need to hire a car for 6 days from barca airport in Feb for 2x adults, 1x 4 year old and 1x 1 year old.

Having looked at the cost to hire car seats, it looks like this is almost the cost of the car rental car itself. One option is to take our own car seats on the plane but as they are both full size this will add to the hassle. Also want to hire from terminal rather than off site rental

Does anyone have any hints or tips on this at all...?
Any help greatly appreciated

[Amateurish]

Take your own car seats. A bit of extra hassle, just stick them on your trolley. The airline will carry them for free. For your 4 year old, you could use a Trunki Boostapak. It's what we use for our little girl. Stick her in flight entertainment into it for the flight, then use it as a booster seat when you get there.

[Urban Sports]

I agree, we always take our own, it's always free and really is very little hassle they just go on the trolley and they take them off you when you check in.

Having seen the state of some of the seats that people hire I'd only be happy with our own.