$5 anti-theft cable lock DIY solution for portable EVSE
Yea, I would feel a lot better about the cable hooking around a wheel spoke instead of the mirror. It's almost a fun challenge for them to break your mirror.
As neither are theft proof (just deterrents), I like the wheel attachment variation because it's less likely to cause damage. I can see the mirror potentially getting snapped off or the black finish marred. The other option I have seen discussed is to simply roll the front tire over the cord. $0.

But could squeezing the cord between tire and pavement cause wear on the cord?
@JetJock, I like your solution and came up with almost the same idea before reading this thread. I considered using the mirror, but like others was concerned about somebody breaking it off. Instead I opted for a longer cable lock allowing me to lock it to the wheel. Another advantage of this setup is you can easily slide the cable lock up and down the J1772 cable and potentially lock it to other "things" like a fence post if you desire.
Here are some pics and basic DIY instructions if others want to copy my setup, it cost me about $5 in parts from Home Depot and took approximately 10min to assemble. I agree this is a deterrent since a determined thief could just get a lock cutter, but it still prevents an opportunity theft and makes me much more comfortable about leaving my $400 L1 EVSE or $830 L2 EVSE (SPX Power Xpress) unattended.
I used vinyl coated 3/16" cable to both protect the rim and waterproof. As you can see below it easily fits in the hatch EVSE stowage area.
DIY Instructions:
1) From Home Depot I purchased 4 1/2ft of vinyl coated galvanized 3/16" wire cable along with 1/4" crimp ferrules, Velcro straps, and a pad-lock of choice (I happen to like the relatively new
Speedial Master Locks allowing fast 1-hand unlocking but will probably switch to a weatherproof lock).
Note 1: There are other cable options including 3/16" uncoated stainless steel cable and 1/4" cable (coated and uncoated). Both would have been stronger (i.e. tougher to cut through), but I really wanted the vinyl coating and could not find any crimp-on ferrules large enough for 1/4" vinyl cable. Also the 3/16" cable is much easier to work with.
Note 2: I deliberated on the best cable length going anywhere between 3' to 6'. Shorter is easier to manage, longer gives you access to more locking options. Ultimately I decided 4' was the best balance, so I bought 4 1/2' expecting to use 3" on either side to make the thimble loops.
2) On one end, insert the wire into the ferrule to create a thimble loop. I made the loop as small as possible. Then crimp using a bench vise (unless you have a better tool available, my vise is the only tool my arsenal up to the task).
Note 1: This requires exerting a LOT of force!
3) On the other end, create a similar thimble loop, this time wrapping around the J1772 cable. Then crimp using bench vise.
Note 1: Adjust the loop snug around the J1772 cable, but leave a small amount of slack so that it can slide up and down as needed.
4) Attach the Velcro strap and you're done!
See more pics in my album here:
http://gm-volt.com/forum/album.php?albumid=54