Am I in the wrong? Options

[Random_Stranger]

Ok, I am pretty much cool with everyone in my engine overhaul class. It is pretty obvious I love my car, as my normal day to day attire has anything related to Toyota on it, from shirts, jackets, hats, to keychains. Today, the first semester guys (which I am in) was in class all day, when we came out on break, I find one of my friends leaning against my car, and the other with is drink on my hood, along with his bag of burritos on it. I was like "WTF?! Get that $#!T off my car foo" and he took it off and was saying sorry. Then I got in my car and went to grab a bite to eat. When I get back, I am near the front entrance of our shop with my car back where I had it, parked out in front of the shop door to bring my car in. Then another guy was leaning on my car and when he did, it made my alarm chirp. For some reason, he looked back and decided to kick my tire to set off my alarm. I am already pissed off at this point, with energy drinks in my system to help aide my anger and frustration/irritation, and upset because the teacher was lecturing us all day when I wanted to get things done. I turn off my alarm, walk over there and the majority of first semester and second semester standing around watching me walk up. I told them "Look, I am not a confrontational guy, but I swear to God, the next one of ANYONE messing (used another word, but whatever) with my car will catch the quickest @$$ beating". Then one guy said "I like to fight" and I walked up to him and said "I'm serious".

After that, everyone except those who were not leaning on my car (and my friends who were that kept apologizing) were the only people who talked to me. Now that I have calmed down a bit, I ask myself, Am I out of line? Or did I have full right to get all mad for people leaning on my car, touching it (after I keep it clean when I come to school and don't want fingerprints on it and stuff), etc..?