Should babies be in car seats for long periods? We don't drive but we have a few events coming up in September (a wedding etc) where we'll be taking baby in a taxi so will need the car seat. The seat fits to our pram frame so I plan to just take the frame and attach it once there, instead of having to take the whole pram as well. Is it ok to do this for a few hours or should they ideally be laying flat as much as possible?