Sir , you can not convince them as they want to get robbed!
I told people all their life life but they wont listen to you!
I went to Honda workshop and asked them what is this tuning when all the cars are computer controlled and efi ? He said nothing just people get the throttle body cleaned / plug into scan tool etc he said that this is not required and people just waste money on this , he further added that on specially Saturday young boys come here for these kind of un necessary jobs
Treat others the way you want to be treated