Before my car was mine I had it Keyed. See the car was originaly my fathers and he let me take it to Highschool durring finals week. I was very upset to find after my test that someone had taken a key across the roof of the car. To make matters worse I watched the kid do it while another sat on my hood smoking a cigarette and then put it out on my car. I was so pissed I ended up going over with a friend and we beet the kids up. Because of my actions we werent able to get the kids to pay for it. I tried to get insurance money for it through the kids, I tried the cops, everything. I was later told by the cops that had I not gone after the kids I would have been able to make them pay, but if I tried that now I would also have to be charged with assault. Hmm assualt and good paint, or let the whole thing go. The decision was easy. Volvo's are not big on the theft ring and have a good security system to them, but still, people be assholes. I have some aftermarket stuff on my car, a stereo system, rims, tires, etc, and I have had little issue over that stuff. The glass is harder to break than normal glass because of a special coating plus I put tint on my windows which will hold the glass together if it is broken. The alarm system is a minimal passive system, but it does get the job done. I added a two way paging system and caller to the alarm so that I can keep the stock alarm and remote but get some real protection out of it. Basicly there is no passive or active alarm system that will stop a thief from stealing your car, and studies have shown that it makes thiefs more likely to go after your car. They found that if thiefs think if you take the time and money to put in a good alarm you must be trying to protect something expensive, alarms are easy enough to bypass, so the cars are targeted. They did a report and found that an alarm system can by disarmed in less than a minute by a good trained thief. The system I have will call the cops, my cell phone, and page the pager if the alarm is set off. You can also shut off the engine by calling the alarm and putting in a code. Its a good system that offers more protection than any other alarm, but I still feel it could be bypassed. The alarm would have to be an integral part of the electrical and starting system in order to be unbypassable.