I put McGard locks on our 28G. The lug nut size is M12 x 1.5. McGard's part number 24157 is the one you want. They are just the right length.

The only problem is that the standard lug nuts use a 19mm wrench and the key for the locks uses a 13/16" wrench.

To solve this, I found a 13/16 socket made by American Racing Equipment (part number 891214) that also has a 3/4 hex on the drive end. The 19mm wrench fits it perfectly. Apparently 3/4" and 19mm are roughly equal.

I just stored the key and special socket in the bag with the jack in the back of the car. It's not near as complicated as it sounds!

Whenever I get time. I'll file down the hex on the key to make it 19mm. That way I can get rid of the extra socket.

BTW I got the locks and and socket at NTB. They matched the Pep Boys price of $23.99 on the locks and threw in the adapter socket for free.

Hope this helps.

I bought those locks and installed them but they looked out of place so I took them back.