Nice, glad to see it on the road again!
Are you talking like grayish black spots on the roof? Mine didn't have those when new, even after sitting near the Jersey shore (Wall Twp) for over two years. Brought it back to MI, stored it inside right away, only pulling it out for a couple weeks a year. It has now developed black spots, and I clean the roof each year before I put it away. It must be something in the air or from trees that cause it.
I have the wrinkles in the corner like you mention, been there since new. Doesn't seem to hurt anything. The seams there seemed to be ok, but I did find this along the side this year:
I haven't filled them yet, I'll get to it in the next couple weeks. I have the tube of Dicor sitting on the tongue ready to go, just need to clean the seam area itself and apply the new. We had heavy storms for the couple days before I put it back inside, so in order to keep the seam dry for those three days and for the four hour trip up to the building, I put some duct tape on the splits. It held remarkably well the whole way, even though a huge downpour, but now I have a little adhesive residue on the roof from when I pulled the tape off.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR