It seems I have been on a never ending quest to find a source for TRUE factory specs on Firebirds, and I was hopeing that this book would be the one because I have heard other people talk about it... But after buyin the book I found a couple errors right off. They probably wouldn't bother the average reader, but for instance it lists there being a total of 1,500 1989 Trubo Trans Ams, when in fact there were 1,555 made. A small error, but it's there. Also, they underrated the HP of my car by 10hp (gggrrrrrr). If you are buying a Firebird, or just want to get an overview of the Firebird line up, this is a good book. It has design changes for each year, and RPO codes, and production numbers. I'm still glad I bought the book, even though it may have some errors (like all the rest of them it seems). Also, the book is almost pocket size, which was surprising at first but really is pretty cool so you can fit it in your glove box and read whenever.