My coach has a vertical seam in the back, don't notice it on the drivers side but that is where the bedroom slide is. I asked the paint and body men at Premire Rv in Juction City, Or. about it and they said it was not a problem with the wall, just is a seam that could have been finished better at the factory. You have to be in the right spot to see it. I've had the coach 3 years and it is still the same.
If you haven't been up on the roof yet, get up there and check all seams, I climbed up on every roof when I was looking to buy and found alot that wasn't right. Go under and check for oil leaks and rust. When was service done, oil change on engine, trans, engine air filter and air pump system filter. When coach has run for while and air is built up open drain valve to both air tanks(one at a time with engine off) and see if any moisture comes out. Have them build up the air pressure and come back the next day and see if it lost pressure, 10-20 lbs not too bad, 50-60 pounds not so good, these things can be fixed and depending on the price and what it is not a deal breaker.
John and Cherrie
2003 Holiday Rambler Scepter 40DST
Pushed By 2003 Ford Explorer