Bass driver behaviour in "leaky box"

[FE3T]

I drive a car the US board users probably never have seen
A 85 Mazda 929 Coupe.

Being a 2 door with the gas tank placed below the rear shelf this is a tricky car to install subwoofers in, especially if the trunk place are needed for luggage and such.

After removing the side panel behind the driver side door in my parts car i discovered that the panel hides a pretty generous space there.
So now i consider to reinforce the area with MDF and install a 10" driver in each of these panels.

2 of the drivers i have on shelves are recommended in sealed boxes about 17-22 Litres (about 0,6-0,75 cuft) wich seams to be pretty equal to the space i have aviable. BUT since i probably would not be able to seal the area completely off, this box will probably be a bit leaky, especially towards the trunk and maybe even to the outside of the car.

Would my woofers still be usable for this use, or would i be better of with a different pair i have wich are more suited towards larger boxes.

[Dealer]

I would recommend drivers with A high mechanical Q, otherwise known as "Free Air" Or Infinite baffle type speakers. The main concern is sealing the rear waves from the cabin, or from the frontal air mass area.
If the area is accessible at all, I would recommend reinforced fiberglass enclosures using appropriate drivers.