How do you secure a tool chest to a truck bed?

I found a used 2018 Chrysler 300C in great condition, but I’m considering buying new instead of used. However, I need to ensure the car isn’t past a certain length to fit in my garage. How long is the 300C?

I just bought a Honda Odyssey and the service manager at the dealership told me to be very careful never to lock myself out of the car. Well I’ve locked myself out of my other cars plenty of times and a slim jim always worked to get me back in, but the manager sounded really serious about it, so I’m wondering if maybe a slim jim doesn’t work on an Odyssey. If it does, is there a different way to do it?

I had some unforeseen expenses this month and I'm not sure if I can make my car note payment. What happens if I miss it?