Once the repairs are completed, you may be asked to sign a COMPLETE release to get your coach back. At that time you have sort of lost all of your negotiating power.
On our vehicle, when we got hit, we settled on the exact amount I would get BEFORE I ever let them start any repairs, etc. As I mentioned, the diminished value took the vehicle from being repaired to being totaled and we got a check for the fair totaled value of the vehicle approximately 1 month after the incident. The entire month that we were negotiating the settlement, his insurance company paid for a rental vehicle. His company was State Farm and I found them fair to deal with.