I think 6x9's would fit in the back. Try Crutchfield.com.
What size speakers go on the rear of a 2001 Buick lesaber
a 1991 buick skylark has 4" speakers in the dash and 6x9's in back
5.25"
they are 4x6 rear speakers are 6x9
The front door speakers in a 2003 buick century are 5 1/4 inches.
The 2003 Buick LeSabre has speakers in the doors of both the driver and passenger side. These speakers are generally about 15 inches.
they used 4"x10"
fronts are 4X6 backs are 6X9
4 inch, 4x6, and 6x9
6" x 9"
4x6 hard to replace!!!
5.25 or 5 1/4