Friend of mine bought a used Civic with aftermarket wheels with wheel locks / lugs. A slim wall 19 fits fine on 4 of the 5 lugs but the last one is a bit different. Any thoughts???

 

I have never seen a lock like that, but the lug nut design looks similar to the "kyokugen-heptagon" style lug nut. The special key for them actually has SEVEN sides instead of a normal six-sided hex. People commonly use a conventional style hex socket on the seven-sided lugs and round them off... ruining them and making it VERY difficult to get off.

Here is an example: https://mackin-ind.com/product/kyokugen-heptagon-nut/