Quote Originally Posted by Sinner314 View Post
I have a 08 Grand Prix GXP that needs a new Passenger door woofer. so i got to looking and i was thinking of doing a new set of 6 3/4 component speaker set with a new A/V type Head unit but i have some questions if anyone can help me.

1. How will changing out a Head Unit affect my HUD ( Heads up Display) i know i will lose the clock in the DIC but is there anything else. Currently i can see my XM/Radio station in the HUD. i also know about using a harness for the door chimes and what to do for the steering wheel controls.

You'll lose the clock feature, plus you"ll the radio/XM stations in the HUD (anything that's associated with the stock radio you loose) this are those two things.

You'll need a GMOS-04 for your module.

Depending on what brand CD player you go with you'll get a PAC or other brand steering wheel adapter and wire and program the steering wheel controls in
2. can i use my existing oem XM/Onstar antenna thats on the roof of may car

3. if i do change out To a aftermarket double din headunit will i lose the center channel speaker in the dash?

Nope you keep that unless you decide to ditch it like me. sounds way better without

4. can i do a set of component speakers in the door without changing the head unit? is there a no cutting solution for the tweeters ( can i use stock tweeter holes)

Sure can but a aftermarket CD players makes a huge difference in sound I recommend it.

The stock tweeters can technically be reused but most aftermarket speakers already have the tweeters built in so stocks not needed.

5. ive seen different sizes listed online for what speakers fit my 08 GXP. Does someone have any first hand knowledge of what sizes are all the speakers are in this car?

6x9 rear. 6.5 in the door. I think the center speaker is a 4"

this is more for audio quality at mid to high volume than beat your block up bass machine. after i do these door speakers and head unit im thinking of adding a sub and amp in the trunk. then next summer throw in some new rear deck speakers and a new center channel speaker and 4 channel amp to power them . my question is how do you guys think just 1 bad ass 12 inch subwoofer from a top of the line brand that eats monster watts (1000+) would sound. im thinking JL , KICKER , ORION, ROCKFORD FOSGATE. any suggestions or ideas?
A good 12 powered by a good amp will sound good but beware of rattles.

I use to rock one Memphis 15" for the longest