If you want to take things to the next level then the X3 Stage 5 kit is for you. Featuring all the same hardware as the Stage 4 kit, Rockford Fosgate upgraded the speakers and minicans to their Punch PM series for even more output. They're including their Power small chassis 5-channel amplifier ramping the power total up to a whopping 1,000 watts and the subwoofer option is upgraded with an additional under seat enclosure that allows for all factory seating adjustments and positions with a 10 inch Prime woofer. If you're ready to be the loudest and baddest X3 on the ride then you've found exactly what you need.