hmm car accident huh... so you dont have that black box?
yes the part you said " i noticed when i looked at the new light, there is an extra connector hanging there " yes that connector goes into that black box... if you dont have that, I dunno where you can get it.... you prabably have to go to dealer or search online.... I dunno what they called... If you do go to dealers, I dont think they will sell that part seperately... they come out with taillight... you might hav to buy the whole thing... but you dont want to buy the whole thing....

Soooo!! This is another idea...
( I did this for emergency )

Take a metal wire about ( ---------- ) <- this long and bent it " U " shape ( not too thin/ about 3 times thicker than paper clip ).
and the extra connector that's hanging out, put that " U " shaped wire into each side.
Do you know wha I mean? when u look closer to the connector, there is two holes each side. Stick it in and tape it so that wire wont come out. and try if break lights come out.