Thin mount speaker suggestions

[custom10nut]

Does anyone have any suggestions on “Thin Mount” speakers.
When I say “Thin Mount”, I’m referring to the Depth or the magnet, and the depth of the mount hole.
What I’m looking for is a speaker design that is no more than an inch deep.
I’m in the process of fabricating a “Gas Tank cover”/“Speaker mount panel”.
After a long debate, I decided to keep my tank in the cab,(the Truck’s an unmolested survivor), and I’m trying to figure out how to get a little better sound from the Stereo.
Right now I have one dual speaker in the dash, two mounted up under the bottom of the dash, and a 6x9 under each seat (buckets).
The sound I get right now is muffled at best.
I’m not looking for a system that will shake to windows, but just decent clear sound.
We all know that there’s room for a large speaker on the passenger side, but no room at all on the driver side.
Sorry for the long story, but I’m just looking for suggestions