Building a Better Car Alarm

I'm new around here, and everyone seems to be really informative. I didn't really know where to post this because my questions at the moment have more to do with speakers. So if this "doesn't belong here/would get more attention else where" just let me know. I'm going to be a senior in electrical engineering at the University of Texas. To graduate, everyone has to take a senior design class where the students design and build something new/usefull. I've been thinking about a design for a car alarm that's substantially different than most current designs. I need an opinion and some technical information of a few subjects before I really begin this project. I was hoping a few people here might just experts in these areas. - I want to know what the most commonly used entrence(s)through which theifs enter and how they do so (smashing, picking, kicking, etc.). - I need information on directional sound. Either pre-existing products or just technical information. - I also need information on creating speakers that mask the direction of the sound souce. I'd really be interested in technical information in this area. - What is the best method for detecting criminal entrence into a vehical? I need the dection devices to be locational also. Any information or links anyone could provide would be very appreciated.

What kind of directional sound are you talking about. Would you want the intruder to not be able to locate the alarm? Here is a link for a website that deals with a directional sound back-up alarm, It localizes the sound to a specific area. I am not sure if this is what you are looking for though? http://www.soundalert.com/pdfs/localizer_revalarm.pdf

I'm trying to find a way to make it seem as if the sound is coming from behind the intruder. I would only need to have the sound come from behind at a few key places around the car. Mostly where the most common intruder enters.