I am trying to find one of those large black plastic grill things that sit on my back window of an 89 firebird. Where can I get them besides a junkyard? And what are they called?

 

They're called rear window louvers and ebay is probably the best place to look. I doubt that anyone makes them anymore and it would be hard to find a junkyard set that's in good shape.

 

Like thegreatJ said I think you are talking about rear window louvers. I actually have one, it was on my 89 IROC, but I took it off because I didn't like it. If you want to buy it shoot me an email and we can talk about it. They are pretty nice they look great on a black car, but they can be a hassle when you are trying to clean the back window. They keep the car alot cooler though I noticed.

 

If you drive your car in the winter snow gets under them and you can't get it out. Also visability is realy bad, I pulled them off my TA and stomped them to death after a cop tried to pull me over and had to use the siren because I didn't see the lights in my rearview. One suggestion, look at pictures of third gens with them on it before you buy, in my opinion the rear glass is way to big for them.

 

In my opinion, the look great on a black car with dark tint and the black 3rd gen Trans Am wheels (the Knight Rider look)...but on anything else they are alright at best, and on some cars they look terrible.

But hey if that's what you like, more power to ya. And they do keep the interior cooler during the hot months.

 

not sure why this poped in my head when I read your post: Rock the Mullet!