This is a common problem among motorcyclists, too.
First, add pigtail SAE plug leads to each vehicle so you can easily plug and unplug the charger without opening the hood.
Secondly, why on earth do they all need to be plugged in at once all the time? Any decent battery isn't going to go instantly flat the second you park the car. Consider just using one maintainer, but move it every month or so. Much less to trip over and much less to go wrong.
Another tactic might be to switch to a maintainer that can be mounted in the car. Some allow this, some do not. The plug can be tucked in so that you can pull it out and easily plug in.
The ceiling drop is a good idea -- you could repurpose a trouble light reel, maybe even mount the charger in place of the trouble light if it's lightweight.
Or if you have to run the cords along the floor, you could put down plastic wiring channel (
this stuff) so the cords are out of the way.
Or maybe even mount outlets into the floor in the correct positions. Not sure this would be practical in a concrete floor, assuming that's what you have.