Most infant car seats can be installed without the base in a car and typically connect with various lightweight (snap and go) strollers making portability via ride-share easy. There are one or two convertible car seat/lightweight stroller combos (for toddlers) that are very popular with urban parents who need to use ride shares. They are also useful when you travel via airplane. For example the Cosco Scenera car seat and the Mountain Buggy Nano stroller. (https://www.youtube.com/watch?v=4LotN7k5T2Q)
