If you only get coax's with a $3000 budget, you are going to the wrong shop to buy your equipment.

I did an install a year ago on an 05 G35 and it consisted of the following in that price range. The prices would be lower now and it sounds great.

Eclipse AVN 5500 $1000

CDT ES-620's $350

Elemental Designs 9.2x for front comps $250

Elemental Designs 9.2x for sub $250

Elemental Designs 10OV2 $250

Wiring and Construction - $400 (He bought a prefab fiberglass box for $200)

 

Double DIN head unit for sure, that's the best part of nice audio to me.

better speakers (maybe a 4 channel amp) and a sub in the back. You can custom mold it to a gap in the trunk as well so you don't lose a lot of space. I'd say changing audio is one of the easiest things b/c most speakers are just plug and play. Running the power/ ground/ RCA's for amps and subs can be a bit tricky but nothing a little guidance can't help.

 

huh... The most important part of a nice audio system for me is the audio?
If you hear car audio with your eyes you will have a hard time getting any better then sony or audiobahn.

 

haha, you know when you read it like that it sounds totally bogus. I meant upgrading car audio and systems and such. yea sound is of course important, but I think a slick head unit is a perfect touch.