One BMW Enthusiast's Companion by Robert Bentley Publishers=$5 plus $5 shipping in the lower 48. Normally $30
http://www.bentleypublishers.com/product.htm?code=gbcc
This is a real great book for anyone interested in the performance of their old BMW car.
It's a softcover book, the binding is tight, but the spine is faded a bit from the sun. All kinds of good info on BMW tuning, especially for 90's and pre-'90s models.
Drop me a PM if you are interested.