6x9 behind Vert seats.. wasting my time?

[XW70]

So a previous owner has already gone to the trouble of hacking two 6x9 shaped holes in the steel behind the rear seat of my vert. The stereo setup i have now does me fine (stock sized aftermarket speakers on an aftermarket head unit), but since the holes are there i thought if i used some cheap 6x9 on an amp with some form of low pass filter and just use them for bass i might get somewhat better low end? Id like to keep my bootspace anyway so id rather not go a sub (Obvs not going to sound comparable)

Any one have any experience with this setup, or even in any other car?

[rcsoundn1]

I would not do it because I do not think the effort would result in worthy output. Will you hear something, sure. Will it be worth the $$ an effort in regards to results, not IMO. So much sound would be lost in the foam, and they are not that big, so their output is not that much.