OK so yet another problem. Now the HUD is going in and out, it'* like someone is turning the dimming switch. However sometimes its so dim that it'* barely even visible at night, sometimes it'* the left half or the right half that is dim or out. When I hit the dashboard it comes back on bright and then will slowly start fading back or blinking in and out. Any thoughts? I'm thinking this is going to be a costly fix...do you have to pull the dash to get the HUD out?

You don't have to pull the dash.

I'd try looking for a bad connection at the HUD box in the dash first, may have to replace the control unit.

I'm not sure if the Bonneville Hud is the same as the Grand Prix but I have fixed 2 of the 2 GP'* I have owned. Very simple fix, it was a cold solder joint on the light sensor. If you look at www.clubgp and search for hud problems they have a very good write up and pictures of what to re-solder. The worst part is getting the board out to solder.

Good luck

Nasty Habit

Did you ever find out what caused the problem with your HUD?