I know w/ w/ o rear brake light...

nut metal, plastic, one and three pice?

whats the diff? and are there more?

have pics?

(please no bs about rear louvers)

 

The difference is in the manufacturer. GM used metal slats with ABS side pieces to give them the one piece look. As you mentioned, the 3rd brake light piece was plastic with shorter metal slats for 91 and 92 and I believe it was just plastic in 86 (around the 3rd light). There are 3 piece louvers available from aftermarket companies that look like 3 pieces and look hideous in my opinion. Some are made of strictly plastic and look cheap and rattle. The aftermarket louvers are not made to the quality standards that GM put into theirs. I have an original GM set that uses rubber tubing to rest on the window and absorb sound. I have seen aftermarket sets that use a foam tape. The foam breaks down over a few months and the louvers rest on the window and rattle.

GM uses clips that surround the glass frame at the top and sides and the louvers attach to the clips. I have seen some aftermarket sets that require the 4 glass bolts be removed in order to install a metal strip that the louvers attach to. This can cause rattles to if the window is overtightened. The glass can also shatter if the bolts are overtightened.

I don't know what else to tell you. I like the GM set.