The only 'just in case' moment that I can really think of is if you needed to take bub to Doc/hospital in a hurry. I say that because I frequently care for my nieces and I don't like driving with them in the car ... it's a silly mindset that I have. I will often get SIL to leave carseats though 'just in case' I had to make an 'emergency' trip.

I love the getting around with the girls without the car. We do the groceries, we run errands, we get all those everyday life things done. We are very well located to PT & the girls LOVE catching the tram or train. If you think getting rid of the car is possible for you I applaud you. Maybe don't make the final decision before bub is born, see how you go initially and if you're managing well more power to you!! So long as you have a 'back up plan' for an emergency I think you'll be fine

If you do buy one, a carseat is one thing that I would be careful about getting second hand. You do need to be sure that it hasn't been damaged in an accident. I would hope that people wouldn't on sell a damaged car seat, but it's hard to know who to trust these days.