HiSo after going through all the stories on here I applied through Canadian High Commission in Mexico but also trying to find a lawyer to apply myself as well...As going through Canadian High Commission, Mexico takes about 2 months I have heard
In which city do you live ? The cost of the PCC is less than 100 MXN. My friends usually get it before leaving the country (usually for Aus and other countries but none for Canada yet). It is issued by 'Dirección General Archivo de dentificación Crimnalistico'.
As this is my first comment, I couldn't add the copy of the certificate issued in Guadalajara. It usually takes around two hours to receive the PCC. Passport, Mexico legal visa/FM2/3/M along with a address proof like power or water bill should be carried while walking in.
I'm not sure either if this can be directly sent to IRCC, (but can definitely be added as a supporting document) or the lawyer gets it from a different issuing authority.