In my opinion whether your car is stolen or not depends on your luck. If a thief is determined to steal your car there is not much you can do, especially if the thief is a professional. However, if you can make it inconvenient as possible, the thief may be put off.
i am using this technique and it work well with kia classic, Khyber, Alto, changan (all cars which have rack and pinion steering system). Normally thief didnt see this lock and he just starts the car using his key or by cutting the ignition wire. After moving the car forward when he moves the steering, he has the surprise of his life that the steering is not moving. In a rush he just abondened the vehicle. THis is a very good technique, however few things to be kept in mind is that you should use tri circle bigger lock and not this small one or old fashioned lock which locks and unlock with the keys. That old style manual lock is very difficult to cut. I personally tried to cut that using a grinder and it took about 10 minutes. Moreover the working space in that area of the car is very limited as one has to lye down putting his legs outside the car and then adjust the position in order to reach that small space. It is impossible to use any sort of hammer there due to limited space. It is even difficult to lock/unlock for the car user during night himself. Your hands will become dirty due to grease of rank and pinion joint. But the method is very safe. But remember to keep extra keys at it will be impossible for you to cut the lock if you lost the keys..
i have seen a honda city at terminal one Karachi airport parking lot with a strong chain tied with steering and brake padel along with large tri cycle lock.Remember, these are un conventional ways to keep the thief away. Or you can do like Mr Beans do to his car. Took out the steering when ever he park his mini austin. Steering can be removed easily by using the wheel nut opener. The nut bolt is of same dia i suppose 14". I am sure thief will not come prepare with a extra steering....hahaha
I as an Auto Technician won't advise you for using the pad lock as i have been through many customers who have used pad locks but it will destroy the steering cross because steering cross has small needle rollers in it and as such it is strong enough to steer the car but even slight obstruction in its movement can cause looseness in the joint. Even if the owner himself tries to slightly move the steering in order to check whether the padlock is there or not, will seriously damage the cross. Steering cross is mated in two parts i.e one with rack pinion and the other with steering column rod. The one which is attached to rack pinion is smaller in size and cost around 900/= but the one which comes with steering column rod is around 3000/= so better think before adopting this technique