I think you can use 2006 & 2005 HID bulbs..every HID dealer I managed to talk to said to use 2006 HID bulb for the low beams I never asked about the high beams.. So don't take my word for it
I am not even sure if the 2008 PT has the same bulbs as mine(2001)?
I think the best way to find out is to first ask some questions from the dealer you plan on bying from
Cheers from Canada eh!