i have a 98 reg cab and i have stock 6x9 and put the same back in. i put pioneer in. and if its a quad cab i think its 5.25 in the back doors.
6x8
6.5 for the front
Crutchfield.com says that factory speakers in the 1998 Chevy Cavalier Sedan are: 4" x 6" door speakers and 6"x 9" rear carriage speakers.
front dash tweeters- 3.25" door speakers- 6.5" rear deck speakers- 6x9"
6x9's front doors and 5.25" in the rear
The front speakers, in your 2008 Dodge avenger, will measure four inches by six inches. The back speakers will measure six inches by eight inches.
the rear are 6x9...if im not mistaken the fron are 4
6 3/4 or 6 1/1
Go to Crutchfield.com and they will have all of the sizes of your factory size speakers for your car.
The dash has 3x5 and the door and rear deck speakers are 6x9. Enjoy. ChicagolandAreaModernMopars . com
You don't need factory speakers. Just buy the same size speakers and install.
My 1992 had 6" Factory Round speakers in the front doors and 6 X 8 Factory speakers in the back. My 1998 has Factory 6X 8 speakers in the back (extended cab) and haven't checked the front ones yet. my 1994 has 6"x8" as well in the front and rear.