Buckaroo Banzai vs. The World Crime League

Buckaroo Banzai vs. The World Crime League was the proposed sequel to Buckaroo Banzai Across the Eighth Dimension, released in 1984.

Plot
The adenture shows Buckaroo's feud with Hanoi Xan, more experiments with Jet Car, explains where Penny Priddy came from and more. It also features cameos of several pop culture characters.

Why It Was Cancelled
The first film wasn't very financially successful.

Result
The sequel wasn't done.