We only have ONE firefighter in our area that is "certified" to install carseats and he works like one day a week, hes impossible to get ahold of. DH ended up putting them in and we are hoping he will have the chance to take it by the firehouse for him to inspect it before they get here. Its funny when DH mentions the firehouse to most people they are like "oh I could do it for you" like hes just trying to get out of doing it or something lol. Do you have 2 bases in each car?
We put 2 bases in my car, which will be the primary car they ride in, and then we bought 2 extra bases to travel if my mom or his are watching them. Then we always have my car set up, and can transfer the other two.
There was only in the immediate area too and I had to wait a few days for the appoinntment. I am sure we could have figured them out, but it was nice to learn a few things and see how the pros do it! ;)
Also you can check with your hospital. Ours has a service that does it for free as well.