Wiring the LEDs and fitting them in the module was a PITA. Putting the resistors upstream would've helped, I'll improve that on the next trailer I build.
Wiring runs nicely down the middle of the Hercules floor supports. And my wooden ones.
Here's the junction I used.
Snaking all the wires out of the modules wasn't easy, and there was a little Dremeling required to make a bigger path.