motorhome leaks when raining?

Difficult as I can't see it.
It seems to me you have missed some areas or the trims need mastic applied. I found that's the best thing go around all trims gutter joint strips etc around the roof area and edges and mastic bead all of them see what happens. did this on my caravan it cured it.
If you also have a roof aerial check around the base it may look ok but water has a habbit of capilary action where two surfaces join and the least hole will suck water in. Good luck

Bob
September 2009