It looks like a stock 04' Pontiac GTO bumper, but has another opening on the right hand side, in case you wanted to have your GTO with Dual exhaust, its not the 05'-06' Bumper, its the 04' bumper with a another opening on the right side

Choices ???

OK u want a 04 rear bumper but u do not want the GTO embossed
in the center like the 05 06 ???

You have 3 options for this both come in body kits.

1st CUT out the rightside to match left . Sept 2007 Hot Rod
Page 88 close up shot & picture on page 84 rear of car

2nd R.K Sports trim

RKSport is rear valance is simply an overlay that attaches around the factory valance & provides dual exhaust outlets. You can see here that the GTO was already fitted with dual outlet exhaust so the factory valance was trimmed to allow the driver-side pipes to exit properly. Of course, the new valance cleans up the area completely once it is installed. The RKSport piece fits right into a groove in the factory bumper cover, simplifying installation & alignment.

link: http://highperformancepontiac.com/tech/hppp_0601_2004_pontiac_gto/index.html

picture: http://octanemotorsports.com/popup_image.php?pID=10025&image=4&osCsid=7105a7f46d203d7c56d7c7f9e811632b

Buy it http://octanemotorsports.com/product_info.php?products_id=10025

3rd::: Side exhaust with NO rear exhaust !

link. http://dominantmotors.com/products/index.html

If u want the easiest way to get dual rear exhaust with the 04 look
GET the 05 with the embossed GTO & fiberglass the GTO over.

This has been done 6 times that l know of.
Most like me go for a Used 05 06 bumper & just install it if not putting a Body Kit. Last 3 AL did have gone to Sweden all still say GTO

Happy hunting.