Adventures of Buckaroo Banzai Across the 8th Dimension, The (1984) - W.D. Richter
Buckaroo Banzai is a rock-star/brain-surgeon / comic-book-hero/samurai/ etc who along with his group, the Hong Kong Cavaliers, must stop evil creatures from the 8th dimension (all named John) who are trying to conquer our dimension. He is helped by Penny Pretty, who is a dead ringer for his ex-wife, and some good extra-dimensional beings who look and talk like they are from Jamaica. Neurosurgeon/Rock Star/Superhero Buckaroo has perfected the oscillation overthruster, which allows him to travel through solid matter by using the eighth dimension. The Red Lectroids from Planet 10 are after this device for their own evil ends, and it's up to Buckaroo and his band and crime-fighting team The Hong Kong Cavaliers to stop them.