Could not remember the name of this movie [Mystery Date]

the only thing I really remember about this movie is that theres a dead body in the trunk. A cop sees blood on the ground and calls the driver over. He has it on his fingers and says " I know what this is " the driver gets worried. The cop says " Its transmission fluid, when it gets sticky and red like this, its time to change it"

I guess I have to watch it again.