I come from a very high theft area in lowermainland of B.C., people will steal any kind of vehicle especially if it is low profile...I also have been in the Alarm/caraudio field for 22yrs (installing and managing). Most alarm systems will not cause a current drain or alternator problem if they are a name brand alarm and have been properly installed. By proper I mean soldered, heatshrinked and not easily accessible when a theft is attempted. Most alarms will also come with "normally closed" relay circuits that will still allow the vehicle to operate in the event of a failure of the alarm, ( this is especially important when hooking up starter disable or ignition disable)!. I would recommend staying away from so-called "passive" immobilizers as they will completely disable your vehicle in the event of a product failure and these systems are often hooked into the fuel-pump circuit which could prove very dangerous should it fail when you are driving! ( ask me how I know!). Most alarms will be relatively inexpensive to purchase but be prepared to budget double or triple for a proper installation. I hope this helps!
Nocones
79 242GT 190ks, 86 240gl 315ks