LF 5x7" speakers ... or anything that might fit
 

Have a 1993 Pathfinder with a rotting set of factory Clarion speakers that I wish to replace. Already swapped out the fronts with my old Chameleons, but the rears are proving to be a problem since they're ceiling mounted and I am very much depth-limited. Factory speakers have a mounting depth of ~55mm or ~2-1/4". Thought my Eclipse 8971's would fit, but it's not even close.

IDEALLY looking for JUST a set of "woofers" or midbass/bass. The truck has a few sub box options, but I often pull out the box and just roll with the factory speakers, so I'd like to have reasonable "bass" from them, hence why I want to stick with 5x7's if possible, but I could probably shoehorn some 5-1/4" components if the magnets are reasonable enough (as well as the price).

So, TLDR:
- 5x7" woofer only (ideally) or a "midbass" functional speaker that fits
- mounting depth of not much more than 55mm (2-1/4")
- power handling in the 40RMS or more range (will be powered by an MRV-F305 probably)

Oh, and I am in Windsor and make trips past London pretty often.

I know you don't have depth to the backside of the speaker, but have you thought about using spacers on the OUTSIDE of the hole? These spacers are made of either thick plastic or wood, and come in a variety of thicknesses. They would go between the speaker and the hole, and can be bought specifically for the size of the speaker/hole. You have 5x7" holes? Ok, buy the adapters, and put the speakers of your choice in. Then paint or upholster the adapter so it doesn't stand out, put speaker in, and put a speaker grille over the speaker. BINGO! You can take the maximum depth you HAD, and add up to 1" to the maximum depth (depending on how thick a spacer you buy). If you want to just put woofers in, use adapter plate, and cut a 'baffle' (wood panel) that is the exact size of the spacer, then cut out the correct size for whatever woofer you choose, and mount woofer to the baffle plate you made. If hole is 5x7", then you can probable squeeze a 5" woofer in, or, if you are willing to cut, cut out original hole, and then buy an adapter ring that will cover it all (probably an 8" hole), then you can in- stall an 8" woofer.

As it turns out, my 5x7 issue isn't depth (I have about 3"), its that the hole was about 1/2cm too small all around. Removed the steel speaker mount from the truck, marked the metal with a sharpie, and went to town. I am not complete yet, but I think my Eclipse speakers are gonna fit. However, one of them is kindof screwed up where the voice coil connects to the meshy wire (those two gooey lines on the cone); not sure if I am going to be able to fix that.

As for spacing the speaker out, I don't really want to do that for a few reasons. 1. The factory grilles work well, and sit flush. They're VERY close to the speaker, I'd say maybe 1/8" MAXIMUM away. 2. I want everything to look as stock as possible as I go to the US relatively often, and I park in pretty questionable areas; if I have visible car audio, it will definitely get stolen.