This was the roof of a 12 year old RV that the seller claimed was stored under shelter and in pristine condition.  As you can see the rubber roof is in terrible shape with the black under-layer showing in the front, cracked skylight, missing plumbing vent-cap, rubber separation around rear roof vent, and a terrible home DIY silicone seal job on the front seam.  All the silicone did was seal in moisture.  The front 6-8″ of the RV roof was completely gone, full of ants and roaches.  Strangely enough, the front bedroom and bathroom looked really good, very few signs of water.  See picture below.