Buying a Kia may not be a sign of losing your mind, it may be a sign of finding that the previously unused "sensible parent" part has been activated. Don't worry, it's a short lived thing, in 18 years or so (I am told) it goes back to normal. But by then you can't remember what normal was like
We bough a Kia for my wife, although we needed a car with enough room for 4 car seats, pushchairs, toys etc. so went for the Sedona. It's not beautiful, and it's a car for the head rather than the heart, but it does do things rather well - it's comfy, has been 100% reliable (much more than my VW Passat bought on the same day), has a reasonable fuel consumption and does not attract any unwelcome attention from boy racer types, or envious paint scratchers in car parks. Similarly it comes with lots of toys - the built in DVD player is a godsend on longer journeys. We also went for the Sedona as it had sliding doors, didn't want toddlers swinging doors out wide to damage other cars, I wish more cars had sliding doors as they are a useful feature IMHO. Driving the Sedona has the extra added attraction of making you feel like a lorry driver - they should put a Yorky holder in the dashboard.
In terms of a 3 door vs 5 door, for tiny car seats (group 0) 3 doors are great, you lift the whole seat in and out and can put your knee behind the car seat and push it right down to get the seat located properly. Group 1 or 1+ seats, not so good, you have to lift the baby in and it's awkward. Group 2 seats, again, become quite easy. All in all, I'd say a 3 door is only OK as a second car.
Make sure your car seat is compatible with the car - I'd always recommend a britax seat as we've had lots of great seats from them, and they also have a fit checker for your choice of car. Mothercare offer a trial service, they will try out the seat in your car and will not sell you a seat that is not safe (even if it means them losing a sale ... ethics in selling are a refreshing change these days).
Finally, congratulations! As Lou Reed put it, it's the Beginning of a Great Adventure. Everything changes when that tiny bundle arrives, I don't just mean the inability to leave the house with less than 2 hours preparation time, I mean the things in your heart and mind that change your outlook on the world. Every day is a learning experence!
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COAST Not just somewhere to keep a beach.
A young loner on a crusade to champion the cause of the innocent, the helpless, the powerless, in a world of criminals who operate above the law.