They have a slim version of the ballast now, wish I knew about them before I did mine. Suppose to be only .5" thick compared to the old type which is 1.5" thick. Here is an example.
http://cgi.ebay.com/ebaymotors/HID-Conversion-Xenon-Kit-Ultra-Slim-Ballast-H7-6000k_W0QQitemZ180203026605QQcmdZViewItem?hash=ite m180203026605
Don't forget to get the led bulb for the parking light. Someone suggested in a different HID conversion post. I got some and they made a big difference.
http://www.superbrightleds.com/mini-wedge.html
I was going to try these bulb for my fog lights. LED Daytime Running Lamp (DRL)
http://www.superbrightleds.com/festoon.html
What do you guys think of the H7 (DRL)? Wonder how bright they will be.
Jay