new carpets are great, junkyard carpets are nearly as good. for the price, i would pick and pull matching carpets and detail them while outside of the car.
btw, that incredible is really just that. i broke a ink pen in my back pocket and stained the seat of my MK3 REALLY BAD, it removed 100% of it and also permanent market, use it sparingly but it works. that detailer is also epic at cleaning things.