Sorry, still haven't done the install yet. My roomie/"landlord" is an ass scratch away from having his garage air conditioned, so I'm waiting to do the work in there. These 105 degree days here suuuck.
Edit: Went ahead and put on the Curt hitch tonight. What a b**** with the wrong tools, poor drill bits, and doing it without the car jacked up. That and the perp. flanges on the outside were a bit more narrow than the mounting locations, thus to snug it tight, there really must be some stress on the hitch and metal to which it is mounted. I hope the base metal yielded into place, taking stress off the welds.
May not take pictures of the wiring harness install. It is clear to me the plug adapters are meant to make the install completely plug/play with no splicing. The Curt application sheet lists this type of adapter as "C1 - Converter" for all Mazda 3's thru 2010, implying the vehicle's circuits have enough extra juice for standard trailer lights. Some other vehicles utilizing LED tails, thus with reduced power draw, specify "C3 - Converter, Powered" on the Curt spec sheet, which includes a separate fused power lead back to the battery. My intuition says they got the spec wrong for our vehicle starting in 2007, where LED's are used, and thus they should have really spec'd a powered converter for the later model 3's. I'm going the LED route on my trailer lighting, and with its minimal draw, this may be the easy out for my application. I'll still be able to test the converter on some standard bulbs as well, and will report back.