I know that there has been a number of postings on this topic, but none of them seemed to offer a simple solution.
I just wanted to let you all know that my dealer has offered a solution to the difficult change out of burned out bulbs in the High Mount (or 3rd) Brake light on NF Sonata's.
When mine burned out in 7 months and only 8000miles(12,000KMs) I called about getting it replaced on warranty. They not only changed the bulb (normally requires 1 hour of shop time) but they cored a larger opening and modified the bulb mount so no I can do it myself.
In fact it is now easier than most of the other bulbs, as long as you don't mind laying down in your trunk.
It would seem this is a fairly simple modification and all dealers should be able to do this. They need a steel hole saw to widen the opening below the light housing and then you can access the bulb without removing the package shelf cover and undoing the trim, wiring etc, etc.
Once it warms up - it's -25C tonight - I will try to take some pic's of the mod so you can see how they did this.
My dealer rocks!
Citizen of the Hyundai Nation