Wow, I just found my old jar of pennies, so here's MY two cents worth.....

I used the original speaker housing so I wouldn't have to screw around with
anything else.  I disassembled the old setup and ripped out the speaker cone
and magnet.  Then I cleaned out the remaining scraps to make it nice and
smooth.

I bought a pair of Blaupunkt 3.5" two-ways and they fit inside the old
housing perfectly.  I glued them in place and used the stock wiring (stock
wiring is OK in front, not in back).

Looks stock, sounds good, easy.  A 3.5" speaker doesn't deliver a booming
bass, but that isn't what it's for.  The big speakers in back do that part.

Bill Marshall
85 GL Tiico "Pandora's Box"
Aurora, IL