I have a 2001 (unmodified) GT with embarrassing squeaky noises, seems more prevalent when cold and non-existent once warmed up thoroughly. Anyone else dealt with this issue? Maybe a good time to start the modification process with underdrive pulleys?

 

Get a new serp belt, it is likley the source of the squeek.

 

open the hood and listen to each wheel and see where it is coming from. it might be a bearing, serpbelt of the ever comon belt tensioner

 

only squeek I notice comes from the brakes and those are new pads!

 

you can have squeek from brakes even if there are new pads on.
most of the time it comes from vibrations and roughness of of the caliper.
getting it adjusted and making sure they are bled right will fix that problem.

 

More htan likley it's your belt or a bearing like previousley stated

 

If you brakes are squeaking, it might be your rotor...if you didnt cut your rotor and it was warped, you just ruined your new pads cause they like match to the messed up rotor and get all squeaky and stuff.