The subject of voiding warranties on new Class B units by doing unauthorized modifications was mentioned in another topic and I though it would be a good idea to start a new topic. The modifications done to the electrical system in the example that was noted were recommended and performed by a dealer at the request of the owner. At least that is my understanding.
To protect your wallet should problems with or resulting from the modifications arise, it would be a good idea to make sure the dealer has consulted the Class B manufacturer about the work to be performed. Find out which party will be responsible for warrantying the modifications and any linked components and get it in writing before the work starts.
Most dealers will have competent and knowledgeable staff. Mistakes can happen easily enough though.