The seat folds down perfectly over the box, and it appears as just molding around the seat to the uninitiated.

Your rig sounds badass for sure! I tow a 30 ft offshore boat ( 15k lbs loaded with fuel and trailer ) with mine, albeit only a few miles from storage lot to the boat ramp a few times a year ( boat stays in a slip spring summer and fall) I def would not use it to tow often or long range