Product review (4 stars): Great Kit, Easy to Install
This was very easy to install and works well.  It only gave me an additional inch or two in the back but it helped nonetheless.  As others have said, you definitely should wear long sleeves when installing the kit.  Also, make sure to use the foil duct tape.  I used regular duct tape and then had to redo the entire thing after I found out it was the wrong kind to use.