12's in a 88-98 ext cab,and the back seat

Like the title says has anyone been able to but a 12 in there ext cab fullsize and keep the back seat?Just looking for some ideas,I've got 2 10's back there,but not fond of the sound.

my brother has 2 12 inch comps under his backseat,i'll get a pic sometime today

a buddy of mine has 3 12" pioneer shallow mount subs in his f-250 4 door and they hit pretty hard

Pics would be great,Wondering if I have 2 raise the seat alittle.