Sounds like you are wanting to purchase a gun to protect your car, not for your Home/Self defense. In that case, I would suggest that you not purchase one...confronting unknown number of thieves with unknown motives that are breaking into your car...with a gun, sounds way to dangerous and too much trouble to me. Being armed conotates too much and may get someone killed, even yourself. Are you really willing to take a life over someone breaking into or trying to steal your car??
Get the attention of your leasing agents, ask other tenants to chime in about the safety issues and try to get them to put up for patrol or for the placement of better lighting or a gate. Personal and property safety are issues that will allow you to break your lease and move and there are local agencies and the internet that will allow you to place opinions and concerns about specific complexes that have problems. This unfortunately will not be the end all to your problems, as crimes will most likely continue...but may not be as frequent.
Now...if you are asking about what kind of gun you may want to make as your Home/Self defense weapon...this is certainly the right place to be and will no doubt create any number of different personal opinions.