As for brands, my advice is to buy EuroSportTuning.com – the dude that operates that internet site is aware what he’s undertaking and only sells kits that make sense. What ever they have accessible is exactly what I’d look at. Insert the hose to the underground pipe till it stops. https://www.social-bookmarking.org/en/the-ultimate-guide-to-downpipes-for-bmw-m3-g80-maximize-performance