you mean that audi-style like 36" LED strip at the top of the rear windshield? it's easy, fundamentally
mounting it is as easy as hanging a picture frame.
wiring it (supposing that you only have a positive and negative lead) is also pretty easy. you'll be able to grab the wires through the trunk from the C-pillar.
if Hyundai's electricians are anything like Honda/Acura, ground is switched and power is constant. so IN THIS CASE, your negative lead of the LED strip would tap into the negative lead of your normal brake light (or either your tails or the standard rear windshield lamp at the bottom) and so forth for the positive lead of the LED strip. this way, the strip functions in tandem with your regular brake lights. I'd double check to see what Hyundai's wiring schematics are first before you do it though. note that this would go for a very basic.... LED circuit without a controller and a green or yellow wire etc etc yadda yadda.