Thank you for your response.
There are 3 main differences between the Volt HID kit and Xtreme HID kit.
1) The Xtreme HID kit will come with a relay harness that will power the ballasts directly from the battery whereas the Volt kit relies on the OEM headlight wiring to power the ballasts. The Xtreme harness will ensure that the ballasts always receive a constant 12V as power is being drawn directly from the battery. Jeepgarage members do get a relay harness with the Volt HID kit when you use the "JG" coupon code though.
2) The Xtreme ballasts will be superior to the Volt ballasts as they use a German processing chip that allows the ballasts to monitor the bulb power requirements on a real time basis. This will extend both bulb and ballast life. Xtreme ballasts also have a lower starting draw and a higher efficiency rating.
3) The Xtreme kit comes with a 3 year warranty whereas the Volt kit comes with a 2 year warranty.
The Xtreme HID Kit
is available with a "Philips bulb" option. This kit will come with genuine German made Philips capsules. These are the same bulbs that are used in OEM HID applications.
You would need to get a 9006 Hid kit to upgrade your vehicle's low beams and an H10 HID kit to upgrade your vehicle's fog lights.
Hope this helps,