What's this old scifi movie?

I watched it as a kid. I am now 28.
The movie was about this guy on a desert planet travelling around in a
vehicle with his female partner which later on dies - melting, and it
turns out she is an android.
The hero fights with a bad guy in the end who is pretty much a semi
human semi machine, and has this rocket launching attachment to his
hand... I hope this makes any sense, I only remember flashbacks of it.

well, it's not cherry 2000, i have also gone with this, although it
features morpheus from matrix which is fun to see, but no, thats not
the movie...
I hope someone can help me... they travel kinda alone in this
futuristic vehicle fighting off some scum on their way...
i really wish i could remember some more :(