Factory Alarm

I bought my 96 328is from a private dealer. I discovered recently that on the passenger side under the dash was a receiver for the security alarm, or so it says. I need an alarm and was wondering if that little box means the car is wired for an alarm already. If so, how do I make it work. I have no remotes or anything. Thanks

You'd have to go to a BMW dealer for the parts to complete the system. But considering the prices they charge, you're better off buying a plug-in solution that's even better than the factory alarm:

http://www.stellaralarms.com/products/bmwsystems.lasso