I have a set of the 6x9 speaker adapters for the rear deck of an e36 BMW. These allow you to mount a 6x9 where the 4 inch was. These were in my 95 M3 before it was totaled. They will work in a coupe or a 4 door, but not in a vert(obviously) They were about $60 new, I will take $40 shipped. PM me for questions.

Do you have all the hardware for them?

There is no hardware needed. Well, you may need screws to attach the speakers, but any small screw will work.

SOLD to me!! Thanks Mike.