I have a couple of underseat sub boxes for sale:
First up:
Brand new, never used Aussie 8" box.
This was $210 shipped & almost a full month wait time. Selling for $200 shipped
Next:
Used, Aussie 10" box. This was a test box for multiple different subs. $65 shipped
Last:
8" 3D printed square...
Bought these on Amazon, installed on 1 wheel and didn't care for the black look.
DPAccessories LCB3B6HE-BK04024 24 Black 12x1.5 Closed End Bulge Acorn Lug Nuts - Cone Seat - 19mm Hex
This is the Aussie sub box that fits under the passenger rear seat. JL Audio 10w1v3-2 subwoofer with grille. As well as a custom amp rack that bolts in where the stock B&O sub would go.
About 2 years old. All parts are included, including instructions.
https://www.stage3motorsports.com/t9365-19-22-ranger-23l-ecoboost-gfb-dv-diverter-valve.html
Pulled these off of my FX4 @ 709 miles. Spare was never used. Located in Austin, TX. Looking for $75/each or $350 for the set locally. Not currently looking to ship.
Thanks!