there is no law against cosmetic modifications so no cop will defect you over a nice looking engine bay or some exterior stickers.
it is possible to put stickers on a stock car, many lancer drivers do it.
clear tail lights do look cheap but they wont get you defected.
good head lights might save your life one day.
not many skyline drivers are rich, usually quite the opposite. i know since buying my line that i never have any money in my account.
having your car too low is both a risk of getting a yellow and if too low can actually be bad for your cars handling so that was a valid point.