I am in US. I think your price is too good. I think you should charge him 500 yuan for this fix. I once went to Chevy dealer in March, 2022, their price was dianose fee $189. I totally agree with your assertion, the mechanic time is money. I have another comment on sun roof, I would never buy a car with sun roof, it is an 'extra' which I never use, why bother.