One of the things that have come to my attention has to do with the concerns over the basement.
Essentially, either the mfg puts together a customized chassis themselves, or more commonly they use a chassis from Ford, Chevy, Freightliner, etc.
Once they have their basic chassis, they put in the basement. The basement (cage) consists of the the luggage compartments, electrical distribution center, battery compartment, and water sewage compartment.
One friend of mine told me about his one year old non CC gas Class A. His house batteries simply fell through the battery compartment, which upset him quite a bit.
When I read about the highly regarded used Country Coaches, they mentioned that at one time the basement, also called the cage, used sheet metal and angled iron, that was not subjected to zinc oxide rust prevention process. I think of this as a weakness among strengths as...this note was found on a CC related website.."NOTE: A preventative care step is to give a good thorough powerwashing of the coach undercarriage after each trip to help prevent rusting in those susceptible areas. This is also a good idea simply to remove road grime/road surface treatments the chassis undercarriage may have picked up enroute (like salting chemicals used in winter months)."
The implications are that if one were to buy a used CC Class A, that would be high on the list to determine if the cage was in good shape or not as to the amount of lack of rust. And actually, I have found that other non CC coaches have suffered from this problem, as found when the rust preventative treatment was scraped off a bit to check on the condition of the cages...and also how they were put together as in my friends case where the batteries fell through.
As to the Seneca, I don't know how this applies, but this particular item is now on my inspection list/understanding list when I purchase a new or used coach, regardless of whether it is an A, B, or C.