you could maybe try disabling the drl module i think every gp has one even with auto headlights but im not 100% sure. That is all i could think of because i had the same problem but i just pulled the fuse and now i have manual headlights.
I wish it was that easy for mine...
sent from my Galaxy S Epic 4G using Tapatalk
2001 Grand Prix GT - stock (for now )
2007 Trailblazer SS - back under the knife , motor #4 on the way