Booster seats are often required for kids up to age 8 or so, often only if they are shorter than 4' 9". But booster seats easily fit in small cars.
The age limit recommendation are a rear-facing seat until 2, then a front-facing seat until they reach something like 65 pounds, then a booster seat.
From experience, three car seats cannot fit side-by-side in really any car, whether front-facing or rear-facing. But booster seats are fine, even in my tiny Fiat 500e. Back in the day, I leased a minivan for a while and then the kids started to outgrow bulky carseats.
The age limit recommendation are a rear-facing seat until 2, then a front-facing seat until they reach something like 65 pounds, then a booster seat.
From experience, three car seats cannot fit side-by-side in really any car, whether front-facing or rear-facing. But booster seats are fine, even in my tiny Fiat 500e. Back in the day, I leased a minivan for a while and then the kids started to outgrow bulky carseats.