First I'm hearing of this in any of the forums. Had mine for three months through many car washes and rain storms with no issues. Probably a defective batch of taillight assemblies and/or seals. Both of your taillights have this issue?
Hi, I've just jumped over from another Evoque forum where the same question has been asked...
Condensation in the lights of modern Land Rovers has been a fact of life for some time - most of the manuals actually make mention of it and say it's nothing to worry about it and it will clear of its own accord. It's not an actual fault, it's just a side-effect of the Goretex breathable membranes that the car lights are fitted with. This means that most of the time the air inside the light housing will be the same air as outside, so the same temperature and the same humidity. However, if there's a big drop in temperature outside the car (such as washing the car, rain, or just night falling after a warm day) then the sudden difference in temperature between the inside and outside of the light causes condensation to form inside the light - pretty much the opposite of when you have a cold can of beer on a hot day. It's the same as when you get misting/condensation inside your car or house windows when it's cold outside and warm inside.
Once the temperature and humidity have time to equalise, the condensation will clear. It's not water getting into the lights, it's just the humidity of the air inside them.