New 5th wheel purchase. I think we have a lemon, need advice

OP also has a poor understanding of Lemon Law. In most places it doesn't come into affect until the dealer has tried 3 times to fix a problem. Trying to call something a lemon without giving the dealer a chance to even see the problem is never going to get you anything. Wanting to get the factory involved even before the dealer has a chance hasn't improved your standing with the dealer. You have been labeled as a trouble maker. It is a little late but a little nice gets you a lot farther in life.