You won't find a thread here.
As part of our community rules
"This forum is not intended to be a mechanism for people to vent frustrations about vendors or sales from private parties. Please settle your differences with the seller, manufacturer and dealer through the long-established legal or arbitration systems or the Better Business Bureau but not through our community."
You may find singular posts praising a certain dealer/ service center but that's about it. You may also find that forum members may PM you, if they have strong opinions about service centers along your route.
There are plenty of other sites on the Internet that do reviews. I'd start with the BBB.