The day I brought my secondhand Landrover home after buying it from a “respectable" Landrover dealer I found that not only the sunroof leaked, but water came in through a seal in the passenger door, the window’s didn’t close properly, the window-wipers don’t go back into position when you turn them off, it had a slow puncture, welding under the passenger seat had come adrift, the casing inside the passenger would fall off when you opened it etc. etc. etc
Anyway my reply when complaining about this was “that’s landrovers for you”

...After many phonecalls I thought the best thing would be to write to the area manager, the outcome being we made some compromises and they fixed a few things...not the sunroof though! I have been told that if you lob some vaseline on the seal every now and again it should help. Personally I can’t really be bothered, I have gotten quite used to being freezing cold (cos of the faulty windows), and sitting on a soggy driver’s seat every morning.