Ya I'd shy away from any key-based/lock solution. picking locks is stupid easy, and these locks don't seem very sophisticated. Also, you could just rip it off. I think the most future-hack-proof method would be to get some security firm to install a pin-locked ignition (like in the transporter! XD) I know they exist in RL, that way no amount of hacking the OBD will be able to start it, short of ripping the car apart to get to the system.
I'm gonna ask about the OEM update, and just be careful about where I park my car. Seems sufficient protection to me. Also never give your key to anyone seems like pretty solid advice. No one, even valets drives this car but me.
E92 ///M3 in Dakar Yellow, M-DCT, iDrive, 220M OEM rims, Active Autowerke Green filter, Turner Motorsport test pipes, BPM stage 2 tune.