How long before your due date did you install the car seat?

We currently have our toddler's convertible RF behind the passenger seat. Planning to put her FF behind the driver and have the infant seat behind the passenger. Once both are installed we won't really be able to drive anyone else. LO is 2 and a quarter so she is fine to turn FF but I'm not in a rush, but also don't want to be trying to install the infant base while in labor.

So when did you put it in? I might just do it this weekend- I'm 37 weeks now.