For the first one, I go to Target and get a beach towel to cover the seat. Dark grey, or some other color that matches the interior. They have quite a selection of size and color.
I also punch holes for the headrest posts, which holds it in place and it's long enough to reach the floor in front...
You can tap/splice into the 7-pin trailer harness for extra brake and turn indicators for the rear.
I did that on my Tundra and I'll be doing it for my Maverick.
The added lights for the Tundra were mounted below the bumper.
EDIT: OOPS. Hybrids don't get the 7-pin connector. Must find another...
It's plastic.
Warm it up a little with heat gun or hair dryer and push it back out from underneath with a small hammer handle or some such, staying clear of the sonar sensor.
Steve