I am thinking of buying a car seat that will fit on my pram chassis but am confused about the 2 hours car seat rule. My (newbie) understanding is that babies shouldn't be in car seats for more than two hours (?). So if you were to take your baby out and use the car seat on the pram does that mean they can't be in it for more than two hours from the start of the journey. After the two hours do they have to lie flat for a bit? and how long before you could put them back in again? Have just realised how neurotic this question is but can't work out if its worthwhile having one that attaches or not! Thanks