Could have been published in the 70s as well, story had an alien who comes to earth to destroy a MacGuffin for reasons although the MacGuffin also gives him great strength and the ability to increase his relative speed such that time is effectively slowed around him.
Not sure how/why but he first appears in a prison where he escapes by holding onto the under carriage of a car driven by a woman reporter/psychologist whom he then coerces into helping him.
There's another alien opposing him but it's in the form of a panther, I think.
He eventually destroys the MacGuffin, which removes his abilities right as he is attacked by the bad guy, so he dies. End of story.
Thanks for any assistance you can render!
