Where you get a chance without rain, also check the curve sides of the lamp as well because I think that's where the slight bow out of the gasket (vs straight) will avoid water intrusion as the recess is curved and the gasket is straight on the sides. To follow my overthinking logic/illogic here, , a slight curve inward of the gasket on the sides should also work just as well.........

I replaced my high brake light last weekend as water was getting into the actual light, but not the car.

The new light came with a bulb, which was good as the old bulb was very black which must have reduced it's visibility.

Why didn't Land Rover use LED's, as it does not make sense to have nice LED rear light clusters on my 2013 FL2, but a normal filament bulb for the brake light?

Even my 2006 Mercedes has an LED brake light in the boot lid, but it is a common part to fail, either due to corrosion or mechanical damage.

Jack frost wrote:

The high level brake light is a nightmare as it always leaks, your best course of action is to drill a 1/2 hole through the spare wheel space

Well the B&Q draught strip seems to have done the job - for the moment anyway, time will tellif it's a decent solution to the problem.

Fitting it was a bit fiddly as I needed to snip a triangle out of the inside edge at each corner point to enable it to "curve" or "turn" around the corner without bunching up, or without the stuff getting stuck everywhere as the snipping was done best without the backing strip and I am cack handed!

The rubber strip is a fraction thicker than the original foam gasket and its "E" shaped cross section provides a triple contact point with the car body. The light clicked back into place without any undue pressure being needed so I think the plastic retaining clips shouldn't be under any excessive pressure.

I can't find the post that suggested draught proofing strip (originally from Lidl's I believe) as I would have liked to thank and acknowledge the poster, Thanks anyway to that member for the suggestion - very helpful!

In case anyone else comes across this, it's also worth checking that the washer nozzle is connected properly. I had water inside the car and thankfully because I had screen wash in and not plain water I could smell it was the screenwash. Turned out the nozzle wasn't connected properly and wash was leaking in every time I used the wash at the back.

The gasket also leaked  FL2 TD4 GS 60 reg Facelift - so many issues
2019 DS. Terribly unreliable.
Sold DS for a 2021 Mitsubishi Outlander PHEV. Fingers crossed....
Sold Outlander for a 2014 SD4 SE Tech because I’m mental
Now greatly regret selling the Outlander. MPG of the FL2 is atrocious and so are the fuel bills. Fun though 😎
Couldn’t afford the fuel bills so back to an older Mitsubishi Outlander PHEV. Significantly better than I remembered it to be…