I do the same thing with a 3' choker cable and 8"logging road gate padlock. I know, the thing is huge. I get crap for it all the time. Call me paranoid. Topless in a huge city with a lifted truck you need to be.
I lock it to the clutch pedal though. The cable is double bolted through the floor under the middle of the seat.

Steering wheels are easy to cut through with a cordless sawzall. Dateline timed it a couple years ago with "the Club", I think it was 15 seconds or less. Wasn't long after that the clutch clubs came out.
Never tried one but nobody has ever messed with mine.