5 1/4". I believe that 6.5" can fit there also but I'm not exactly sure how.
go to cruthfield.com
AnswerShould be the same as the 03-04 in which case the front speakers are 6.5" and the rear are 6x9'sTry to use the Hyundai Tiburon speaker adapters plugs so you don't need to cut wires and mess up the electric system, you can get those from eBay or amazon.
According to Crutchfield the front speakers on a 1999 Tiburon are 6 and 3/4 inches.
6 3/4 in front 6x9 in back
Go to Crutchfield.com and they will have all of the sizes of your factory size speakers for your car.
You don't need factory speakers. Just buy the same size speakers and install.
fronts are 6 3/4 rears are 6x9
2006 E250 speaker size is 6x8"
The dash has 3x5 and the door and rear deck speakers are 6x9. Enjoy. ChicagolandAreaModernMopars . com
6 x 9"
6x8
you can go up to 20 stock