3rd gen jbl question

Would it be ok to tap the rear speakers into the dash? Would that level out the sound? Has anyone done this?

 

No, your speakers are 2 ohms, your factory amp is rated at 2 ohms, by linking the rears into the front you will either half or double the ohm load (depending on how you wire them) So you will either present a 1 ohm load to the amp and it will overload the amp, or you will present a 4 ohm load and it will cut the volume by more than half **.

** if a amp provides 100 watts to a 2 ohm speaker, it will only be 50 watts to a 4 ohm speaker, but since we have 2 speakers presenting the 4 ohm load they will get 25 watts each