Let the dealer handle it from beginning to end. Only inform them that they will have to let you inspect it at each key stage (tear down, structure repairs, re-skin, etc) to verify competent repair.
If you make them pay for repairs at another facility, should a problem arise, they would inform you to contact the repair facility and wash their hands of any future liability. If they were the POC for all of the work, then THEY would have to get any future repairs done for you.
Get it in writing that these repairs are covered by them against faulty workmanship for life.
Beyond that, do not ever take delivery of the coach (no matter what) in the event you do not agree with the work. Once you've left the shop, your likelihood of successfully lobbying for rework goes down significantly.
If you have a trip coming up, I would inform them of the trip, show them any reservation receipts and inform them that they would be responsible for either ensuring the repairs are competently done prior to that date or they will need to provide you with a rental.