I used "kextstat | grep -v com.apple" to find active extensions, and found the following listed extensions.
119 3 0xffffff7f826c7000 0x3e000 0x3e000 org.virtualbox.kext.VBoxDrv (3.2.4) <7 5 4 3 1>
121 0 0xffffff7f8196c000 0x8000 0x8000 org.virtualbox.kext.VBoxUSB (3.2.4) <119 35 28 7 5 4 3 1>
I want to unload them with kextunload in order to reduce kernel memory usage, but there are not any org.virtualbox.kext.* files present in my /System/Library/Extensions/ directory. Any suggestions on how I can find where these are being stored and unload them?