Kindig/Kevin Hart Challenger

I guess you are confusing your personal experiences with a totally different situation. Once again the point here is a person doesn't know unless they personally see it. So that would leave you out as I am quite sure you didn't. I see detailed free estimates all the time at body shops everywhere...and they are a must for collision repairs and most especially for factory warranty paint defect repairs done by independent shops when a dealership doesn't have a paint shop. I actually have to use General motor's warranty paint claim policy and figure the estimate and then present it to a body shop and compare it with their estimate before a warranty paint claim repair can take place and be processed. This experience has nothing to do with you.
I think where you are confused and what you're missing is they told you to piss off without telling you to piss off. They have higher sold jobs in line and have zero interest in doing budget paint jobs for anyone. As it would happen I actually manage a GM body shop, as well as do all of our paint work, collision, and warranty.. and am a certified GM refinish tech as well as certified GM/Akzo Nobel Autobase and Autowave warranty refinish tech so I know the GM paint warranty program very well. I would also suggest that you move into the modern repair world and refer to your "estimates" as repair plans... repair plans are less negotiable than the word "estimate".