I had taken my customized Honda City V1 1.3L for a service and the technician (Amit and Manjunath) were reluctant in taking the car for service. They asked me to take the car back to the place where the mods were made, when i asked them if there is a specific reason for not accepting my car for service they quoted that they cannot guarantee that the issue will be fixed and they are not trained on servicing cars with custom header.
Finally, I had to speak to owner of the showroom to convenience the technician to take the car in for service which I think is not reasonable.
The so called authorized service provider for a brand like Honda was not ready to service the car they sold a couple of years back.