Chances are that you're living in a city and/or state that's banned using your phone while driving, and because of that, many manufactures have added a "car mode" to their devices. In most instances, this mode is simply an app that simplifies your phone to its basic parts so you can navigate, make calls, and play music, limiting the amount of smartphone distractions.
This is great for most people, but sometimes when you're driving you need a little more than that. By default, when you start up "Car Mode" on your HTC One, you will be locked in until you exit the app. That means no access to your notification shade or multitasking until you tap exit, and that could be pretty annoying.
Luckily, developer Elad Avron was sick of the restrictions and created an Xposed module to lift them called HTC Care Mode Xposed. While the name may be a mouthful, the module itself is quite simple. It brings back multitasking and the notification shade, along with a few other features.
Install HTC Car Mode Xposed from the Download section of Xposed Installer and, when prompted, tap Activate and Reboot from the notification shade. Alternatively, you can grab the APK directly from the Xposed Repository online.
Now that you're rebooted, you can get to customizing. From the main screen of Car Xposed you will see the option so to re-enable the statusbar pulldown, along with multitasking. Some users have reported this as being buggy, but I haven't had any issues with it on my M8.
You also have the option to change the default behavior of the Home button. This means that rather than being brought back to the Car Mode default screen, you'll be taken back to your home screen. To make it even easier to get out of Car Mode, you should also enable Exit without confirmation so that you no longer have a popup every time you exit.
There are also options to startup or shutdown GPS and Wi-Fi when entering Car Mode, so if you use navigation often, be sure to enable those. The developer plans to add more features in the future, so don't forget to keep checking for updates!