New deck or no new deck??

Well I have a 2002 Mercury Sable LS premium. It came with the premium Mach system already so I dont think I am going to change the setup on the speakers, but I would like to add a sub. My question is should I buy a new deck for the Sub or is it possible or even worth it to hook it up to the excisting stereo setup. I realize most wouldnt even think about it, new deck? Right, but problem is that the sable has the electronic temperature controls and is integrated with the radio. Soo if I put a new deck in it would have to be relocated to somewhere else which would not only take up more space but wouldnt look all that great with two radios. Let me know how worthwhile it would be to get a sub hooked up to my excisting stereo.

if that center dash piece is the same as the 98 they have a kit for it so u can install an aftermarket head unit. Then all u need is a sub and an amp. check www.crutchfield.com

Generally, a sub sounds better with an aftermarket head unit. I believe PaulD could list some exceptions to this, though. I think Honda stock units are one of them.

the secret of integrating a stock headunit is a good LOC, a poorly designed LOC (line output convertor) will act as a high pass filter ...... that means it will cut your bass, possibly quite drastically. The other problem is a LOT of headunits have built in EQ'ing.