The rack

It took the whole morning, but it's installed:

I'm about to order a new spiffy cover for the spare tire. 

The unit seems very sturdy.  Putting it together involved my first adventure with a torque wrench, and going off to Home Depot to get the right size metric wrench sockets.

I've ordered the light kit that these people sell.  It runs off the trailer light connector and provides running lights, turn signals, and brake lights.  Although the unit doesn't obscure the rig's lights, it does stick out a fair way and I'd like people to see it.  I'd like it even more if it had back-up lights, but I think that's another project.