Very good point, the install is the critical, good alarm great install makes the system more difficult to infultrate. Great system not so good install makes the system very easy to get around. Definatley look into the work of the installer before you let them touch your car, I'm sure if there work is great they would have some vehicles to show you. As for systems Viper does make great systems at very reasonable prices and technology wise, I believe the best in the business why, they are the largest manufacturer of auto security in North America, most of the vehicle manufacturer's are now going to DEI (Directed Electronics Inc) the manufacturer of Viper, Python, Sidewinder and more, to make there systems. I've sold DEI products for almost 10 years and if done right I get the least amount of headaches with there systems. If you have a big budget and want a really cool system look into the Compustar by Forcetech, very cool system range 1/4 mile no problem, status indicating paging system etc...
Good Luck
