It's possible to defeat a transponder immobiliser, but very tricky to do. In the case of the Laguna II, you'd probably have to come equipped with a pre-programmed key and
and possibly a
, and then you'd have to fit them to the car. That's a bit more involved than just using brute force to break the steering lock and then shorting out the connections on the ignition barrel.
For a car like the Lag II, it's not practically worthwhile taking the effort to steal one. If you have something really expensive or really special, then the crooks would normally tow it or stick it on the back of a truck and replace the appropriate components at their leisure.
For mainstream cars, the trick these days is to steal the keys, mainly by 'hooking' though the letterbox (never leave your keys in the hall) or breaking into the house and finding them. It's not unknown for car keys to be stolen from gym lockers etc. and the owner's car subsequently stolen.
This goes to show how difficult it is to steal a modern car without having the keys - it now makes far more sense to steal the keys.