First answer is never buy new...that said anyone here who is honest will tell you that a trouble free coach does not exist. The weird thing I/E is a reality trouble free Monaco for some may be a mess for another, same year, same model. Inspect anything you want bumper to bumper. If your in larger population area consider craigs list for an independent tech. Also consider a tech from a co who has good rep where you live. For 300 to 500 you get a great look at the unit from a person who has no emotional attachment to the deal.
Still not comfortable consider a service contract for future problems.
Ft and luv in it
Jw