Alien 51

Alien 51 is a 2004 lowbudget science fiction film starring Heidi Fleiss.

The movie opens with a woman being chased through the desert by an unseen creature, but then she wakes up revealing it to be a nightmare.Traci and her boyfriend Gibson are driving across the desert at night. Gibson keeps talking about Area 51, but Traci is only interested in reaching Las Vegas. In order to get Gibson to shut up and keep driving, Traci takes her top off and straddles his lap. Because of her distraction he runs over something, blowing out a tire. Gibson stops to change the tire, but immediately vanishes when he gets out of the car. Traci searches for him, but only finds a bloody tire iron. She runs back to the car, lights a cigarette and drives away. However, she soon has an accident and is trapped by the seatbelt. The monster picks up her cigarette outside the car and ignites the gasoline leaking from the car, setting it and Traci on fire. ........

Source: Wikipedia