this is kinda weak solution but i did it in my cutlass supreme. To make sure i had enough clearance i cut out the some of the board on the rear deck so my tweeter wouldn't get crushed. Now to mount them i used the 6x9 brackets off my Cutlass ciera and hooked them in where the 4x10 bracket was. the only problem was that where you lock it in place wasn't right so i used some heavy cable ties to hold it up in there. from in the car you could never tell cause the rear deck was carpeted unlike my monte carlo which i just got some 4 x10 cause i had to use the speaker grilles. It wasn't pretty but i never had a problem.