The outer right hand side LED was intermittent on mine
I removed the tail light
You slide the black plastic piece to the left of the right tail light (or to the right of the left tail light) upwards
When you remove it, you reveal the 2X 10mm bolts
Removed the tail light, and since it was intermittent, I didn't think its was a soldering issue
Sure enough, the led panel has 2 gold colored contact points
I used sand paper on both of them
And cleaned the corresponding part in the cover that houses the bulbs
And bent them slight light outwards
So they would be touching those gold colored contacts points with more force when you reattach the bulb holder to the tail light
Sure enough, both tail lights work now
While I was there I also cleaned out all the bulbs with a tissue and some alcohol, since the bulbs were a little dirty
Also did the inner lights as well
Car looks good as new