A Boompa Blog http://www.boompa.com http://www.boompa.com/63cat/blog/&blogId=3386 I found out what the bottle in the engine compartment is. When Buick built the Wildcat, evidently they came up with some pretty innovative ideas. The bottle is for extra windshield washing fluid. When the main resivoir is empty the owner pours this into it. Gib at Buick-World where I get my parts told me this. 2007-01-07 10:49:41 en-us