I am just about to go off to university and i am soon going to buy and alarm. What is important to have in an alarm like what sensors are best to protect your investment and who makes the best alarms?

A paging alarm system is the place to start with. I prefer, use and recommend Compustar. Install is what sets of a alarm in the first place, the better the install with the proper parts = more reliable security. Add things like a self powered siren, that way when the siren wires get cut on the main siren, the second self powered siren is still going off (they are loud little suckers as well). Ensure that the factory door pins are working properly, same with the dome light as they are all hooked to a alarm system. Ensure that the impact sensor is set properly. This is not a rock the vehicle sensor, a thief is not going to shake his way into your car. A digital motion sensor is a good idea as a back up to the impact sensor. You must have a pinswitch on the front hood, otherwise up goes the hood, snip goes the siren wire and away goes your gear (another reason for a self powered siren here). Interior strobe lights work great as well as it makes it hard to see what one is doing. Multiple led's so that Mr. Thief knows that there is alarm there. A glass break sensor is a must, used when the thief uses porcelain on the window (which does not set off 99% of impact sensors).

Lots to consider, mostly add on options. You get what you pay for though, go cheap, expect a poor level of security. Get a crappy install, get piss poor protection. Pay for good gear and a good install with the proper options and you are protected far better.

My Uncle used to work at Sounds Around in Calgary and the one thing that he ran into is that a glass break sensor is extremly useless in Canada during the winter because some of the sounds the vehicle makes ajusting to the temperature set the alarm off. Has anyone else ever ran into this problem?

A good glass break sensor is tuned to a specific frequency. A poorly tuned or manufactered impact sensor generally gets set off by winds and other vehicles, loud exhausts, bass etc.