4x6 to 6.5 adapter?

[sciroccos at earthlink.net (Jim Ruffi)]

Just fired up my new Kenwood receiver I bought for the drive out to
Cincy...looks/works great so far, with an AUX input for my MP3 player, which
is sweet.

I'd LOVE to put 6.5" speakers in (under) the 4x6 rear side parcel area in my
car but, to my knowledge, there has never been an adapter.  Has anyone ever
tried this?  I want to do this without any cutting, so I'm talking about an
adapter.  TIA

Jim