[Outwest34au]

It appears that BMW, Suzuki and Saab at least use electric/ electronic steering locks. These are apparently hooked through all sorts of circuits and sensors. A bit of a google brings up some tales of woe from users who have had a fault light come on and the lock fails to work as a result.
If the big boys can't get that right it might be a sign to avoid that idea.

A couple of those woeful tales below,
"2003 saab 9-3's steering locked while driving on the highway**cc when the steering locked, the consumer crossed into the oncoming lane, hit a snow bank, a snow ramp to a flower bed, went airborne and hit a wooden business sign, crossed to more properties, and came to rest on the rear end of a pleasure boat. the computer on the vehicle read steering lock malfunction. the consumer had no control over the vehicle during the accident; when the vehicle stopped the steering worked again, but the message steering locked malfunction remained"

"While driving vehicle stalled, and the steering wheel locked. the cause had not been determined."