21. This is what our final trunk-mount nitrous-bottle setup looks like. It's securely fastened to the trunk floorboard, has a bottle heater (optional) with necessary wiring and remotes, is mounted at the correct angle and has an inline nitrous psi gauge. Simply open the main-bottle valve, arm the system by way of the in-cockpit switch and hold on. Note: Whenever you're done with or not using the nitrous system, always turn off the main-bottle valve. This prevents the high nitrous pressure from exerting unwanted force on the small seals in the nitrous solenoid, which can cause them to swell. In other words, don't leave the bottle turned on overnight.