Tough when you've got 4 kids (3 who need car seats). I often see families with 3+ kids in the parks, so I know we're not alone. Admittedly I've only taken an Uber using a car seat a handful of times, but each time has been a hassle (having to wait for them to retrieve the seat from the trunk and actually install it). And I've never had one with more than 2 car seats available (we had to wait a while for it, too).