u/DueCorgi7643

Looking to do big 3 upgrade what’s the best way of doing it not a lot of videos on the mk4 do I sandwich (stack) all the grounds and the oem alternator wire with the new power wire but connect the power wire directly to the battery so that everything still runs in parallel and i keep the oem harness functions like the battery light and on off sensor or how would I do it

My friends dad is selling his s3 due to them moving across the country the car in the exterior is really clean and seems to be well taken care the mileage unfortunately is high but I do know the ea888 is a good motor with the proper care it has a mrbp exhaust and neuspeed intake already installed as well