I have an 07 Acura tl and looking to put a new sub in to enhance my sound in my car .... I have the stock deck still in and don't really want to replace it ... Is there anyway I can hook up a new sub and amp to my stock deck ? Thanks for whoever helps!

 

yes, rasperry.
you'll need a LOC, or a line out converter.

then, you disconnect the stock sub. use the stock sub wires to wire in the LOC. then the LOC will connect to your aftermarket amp.

or, use the high pre-amp signal from your aftermarket amp and connect it to the stock amp.

choose your poison.

 

Thank you! Is this going to cause any problem to my battery/car?

 

yes, if you leave the radio on with out the car being on.
use common sense.

 

By any chance do you know what size or have any suggestions for new door speakers?

 

any 6.5 speakers will fit inside the door.

and yes, it will cause problems to your battery,
if you leave the radio on without the car being on.