Summary
UPDATE 2019.04.21

Be sure to check out this power converter mount designed SHaFT7: https://www.thingiverse.com/thing:3579490

UPDATE 2019.01.22

After some good feedback from a maker, I've designed v2. v2 is more slim, doesn't get in the way of Z-axis calibration, and has a full clip on wrap around the upper crossbar.

ORIGINAL 2018.12.08

This is my take on a lighting system for the Prusa MK3. The light bar mounts on the back side and provides great illumination on the print bed.

I also designed so that I could still support dual Mark3 Spool Holders without any interference: https://www.thingiverse.com/thing:1832235

Print Settings
Printer brand:
Prusa

Printer:
i3 MK3

Rafts:
No
Supports:
No
Resolution:
.15mm
Infill:
20%
Filament brand:
Prusa

Filament color:
Orange

Filament material:
PET

Notes:
Lightbar requires the following items:

*** YOU CANNOT WIRE THE 12V LIGHT DIRECTLY TO THE 24V EINSY BOARD OR POWER SUPPLY - YOU MUST USE THE PROPER POWER CONVERTER!!!

2 printed light bar brackets
2 zip ties
1 x 12V LED Light Bar (I chose these because I like that they have a built-in on/off switch - https://www.amazon.com/gp/product/B07BN1ZV12/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
1 x 24v/12v to 12v 5A Power Converter - https://www.amazon.com/gp/product/B01N5KN3FN/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
Optional Techflex -https://www.amazon.com/gp/product/B00C5NS8Z4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I mounted the power converter to the back of the z-axis bracket using one of the screw holes already present. Then secured the IN wires to one of the 24V lead pairs on the Einsy board utilizing terminal connectors on the wires. I then mounted the light brackets, secured the light with zip ties, and then wired the OUT leads from the power converter to the leads on the 12V light.

Now, the light will auto on/off with power to the printer, or I can press the on/off light switch built into the light bar for manual on/off while the printer is running.