I have so much in my trunk because I like being prepared and i know that if I just have the tool I can fix or diagnose it and be on my way. When I travel to see my family in Houston, from Lincoln NE, its about 900 miles one way. When I do that I load up the trunk with all my tools. Full mechanics tool set, dewalt impact wrenches, hydraulic jack and jackstands... I also have AAA but I don't like having to wait around for help. I haven't had any serious problems outside of town, but I did use AAA when my transmission blew. You can't prepare for everything. I also have a habit of getting cars stuck in snow and mud so having tow ropes makes it easier to find someone to pull you out. And if you have ever had a brake line blow out the comfort of carrying spare tools is never annoying.
1997 BMW 540i