venting sub through rear shelf/bulkhead?

Hi all, I've got a '98 UK Escort 4dr Saloon. I want to add some kind of sub to it but i'm under the impression it's fairly pointless throwing something in the boot as there is practically nowhere for the sound to get into the cabin (and pushing against the OE rear shelf speakers probably isn't the best idea)... So I'm wondering if it's practical in any way to build a box that bolts to the underside of the rear parcel shelf (remember this is a 4dr saloon, not a hatchback!) and then uses the OE speaker grills on teh shelf to vent through.. I assume the speaker itself would sit either inside the box, or hang down from it.. I've not seen this configuration before so perhaps it's not valid? Any advice or experiences welcome... Thanks!

unless the car is rock solid and has a solid wall dividing the cabin from the trunk...the trunk is the best place for subwoofers

I've not suggested having a sub anywhere other than in the trunk..

I mean you can keep your rear speakers and still have plenty of bass.

Ok well i've bit the bullet and purchased a pair of Tang Band w69-1436's which I will put in a slimline box bolted and sealed to the underside of the deck, with the subs working through the OE speaker holes on the deck. [url]http://www.tb-speaker.com/detail/1230_04/w69-1436.htm[/url] Fingers crossed :)

I'd rather get these if you can find them...higher xmax and http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=264-837

sagmaster, try mounting the TB's and going ahead with your plan sans the slim sealed boxes that you intend to contain them in.  They will perform much better if given the large amount of airspace the boot cavity affords.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

stevdart wrote: sagmaster, try mounting the TB's and going ahead with your plan sans the slim sealed boxes that you intend to contain them in. They will perform much better if given the large amount of airspace the boot cavity affords.

Well ok, I can do that as I bought some 6x9>5x7 adapters with the speakers which means I can simply bolt them straight in. It's worth a shot.