Congratulations, on your new born baby. Personally, I would never allow a infant, in the front seat, of any vehicle. “Airbag” They belong facing rear wise, in a backseat of a vehicle. You might be able to put a umbrella stroller in the rear of of a smart car. I doubt a full size one. Then you got all the other necessities, diaper bags etc. That go along with infant care.
If your driving a older 451 smart car, and plan to use that seat. Go to the owners manual. Page 42-43. Child restraint. You’ll need to turn of the passenger air bag off, on that side of the car. There are full instruction, on how to do that.
Please keep your new born safe.