The most important thing that you can do to ensure that you will be working with a competent contractor or dealer is ask for references. I would ask the Dealer or Contractor for at least 3 refences of jobs that they have worked on in your area. The first reference being the most current job that they have completed. Ask the customer if they were satisfied with the dealer. How long did the construction project take to complete. Are they satisfied with the home that they had constructed. Did the contractor stick to the schedule that was given to the customer. Did the contractor correspond with the customer on a weekly basis to keep the customer in the loop as far as progress being completed on the job. Did the contractor show progress on the jobsite every day until the project was completed.
A sign that you will be dealing with a bad contractor is if references state that the contractor left the jobsite to go to another job prior to completing your home.
Talk to a reference that had their home completed over a year ago. Find out how their home is holding up after living in it for a year. Did the contractor provide adequate service to deal with any punchlist items after the job was completed?
Request a couple of references for vendors the contractor does business with to supply the jobsite with materials (i.e. Concrete, Lumber,etc.). Does the contractor pay bills on time?
These are all valid questions that a customer has the Right to inquire about before signing a contract with a contractor.
The more research that you do prior to signing with a dealer or contractor, the better your chances of having a smooth running construction project.
Always remember, the sweetness of a cheap price never out lasts the bitterness of poor workmanship.
It is always a good idea to get multiple bids from different Dealers & Contractors. Let them know this up front so they can deliver a competitive Bid for your project. Best Wishes, Matt.