Wow, in NY they take the whole car.
Alarms and what not are useless. Cut switches are the best form of protection. My dad used to be an adjunct proff. in a prison, so he asked the guy in for grand theft auto how to protect it...
Here is what he said:
A professional will carry a laptop computer and can get into any car with a factory combination lock (a lot of fords have these) cause the combination is stored at the central FORD database. 2nd easiest thing is to come with a flatbed truck and just pick the whole thing up. A professional will get past any protection. As for kids, the club and a cut switch are best bets.