Last weekend I went to a E30 BMW gathering in Asheville. It was the farthest I have taken my car and at the limit of my range. I charged the car while I was there and was able to make it back home. About 30 or so cars showed up. The car was a hit and quite a few people were very interested.
This inspired me to finally wire up my J1772 receptacle so I can extend my range. I wanted the J1772 receptacle to be rigidly mounted to the car and also keep my NEMA receptacle. I did not have a great spot to put it that was accessible from outside the car so I put it in the trunk. When I am charging with J1772 (very rarely) I will just rest the trunk lid on the cable. I wanted to be able to switch between the J1772 receptacle and the NEMA twist lock. This prevents the second receptacle's leads from being hot while the other is charging. The switch I used is a ON-ON switch that breaks both lines. Looking back I wish I had used an ON-OFF-ON switch, but it really doesn't matter. To turn off the charger I just change the switch position to the other receptacle. I used a 1N4003 diode and 880ohm resistor between pin 4 and ground.
I found these links to be good references for the J1772 wiring:
EVTV
etischer
bruceme good reference, but I really think you should have a switch for connecting/disconnecting your charger
I also got my gauges properly mounted. I took a scrap piece of aluminum I had lying around, used a hole saw to make some 2" holes, bent the ends and wired everything up.
Since my gauges moved out of the radio slot I put a CD player in. Now I have something to listen to on my commute.