Graco extendable car seats

We got a regular infant car seat to start with so we could use it as a carrier (instead of unstrapping and carrying him into places). However, I'm thinking about getting an extendable car seat once he goes to front facing.

My question is - how easy is it to take the them in and out of the car? Do they have bases they connect to like carriers? We alternate who takes him and picks him up from daycare so we'd have to have something that can easily be taken in and out and I don't want spend $300 or more on 2 separate front facing car seats. If we had to do that I definitely wouldn't get the extendable ones.

I haven't looked at them too much and don't know anybody that has used them.