I'm curious, at 6'4 I had to sell my M5 and jump into a G12 750i to get the clearance I needed.
My wife is 5'6" and she's barely clearing the driver seat with a rear facing car seat in the back.
Ideally, you'll want an infant car seat with a base, makes life so much easier since in the early stages they stay in their carriers most of the time while out and it's nice to just clip it into the stroller.
Here is my setup currently.
Infant
Graco Snugride SnugLock 35 XT
We got the travel system so came with the matching stroller.
Since they both outgrew their infant car seats, they now have this. One of my kids is now forward facing so that made a huge diff but in an M5, my kids legs touch the back of my seat. I can't be all the way back.
For my daughter, she's still rear facing and in an M5 my wife at 5'6 can only sit passenger.
https://www.buybuybaby.com/store/pro...r-seat/5196922
I'm waiting till they are both front facing to jump back in an F90 M5. It sucks balls. I read that the car seat manufacturers tested these against the national average of 5'6" for height. That shit needs to be updated.