Depending on the model or type of car alarm and security that you are going to install, you’ll have a much better chance of success when you have it professionally installed. This is especially true if there are connections that have to be made with the other electronic components or accessories of your car such as the stereo, windows, heating and air conditioning, and lights among other things. But if you’re pretty confident about your knowledge of car electrical systems, then you can easily follow the instructions on the car alarm owner’s manual.