what do i need to replace my rear tail light that is cracked? do i need to buy the whole tailight or do i buy a cover, tail lamp assay, wiring harness? can someone explain to me what the parts are?

 

The whole assembly needs to be replaced.

Remove the bulbs, and keep those... Search ebay/LKQ for a tail light assembly.

New ones at the dealer are $$$$

 

Depending on whether you wish this to be a show car, or a daily driver, you might want to check into X-Pel Technologies protectant film. They will sell it by the sq inch, probably around $50 for enough to cover both tail lights. ( I couldn't find a pre-cut set for the tail lights )
( assuming you are a DIY type )

XPEL Technologies Corp.: Paint & Headlamp Protection Material By The Foot

look under the headlight protector category and measure how much you will need to cover both tail lights.

 

damn, i was hoping to only be able to replace the plastic cover which is the one that is cracked the fog lamps are also cracked and those are expensive also

 

I have considered doing this also, I was thinking about adding a tinted color to try and cover up the crack. would a tint look ok?

 

I have seen tinted tail lights on a couple of the black cars - don't look too bad ...
Not quite sure just how legal it is, however. Best check your state laws .....