Lunar Roadstar EL 2018.

[Rocket.]

We bought the above motorhome new, in 2018, just prior to lunar going bust. It's everything we hoped for and suits us perfectly. Just two slight niggles: first, water from the kitchen sink takes ages to drain away, secondly: rainwater pools above the cab resulting in a waterfall over the cab doors.
Just wondering if there are any owners out there who have the same issues, and is there a resolution?
Thanks for taking the time to read.