David and Claire drive from LAX airport to the estate in a station wagon. In the closeup shot of the two of them from the front, the car has no rear-view mirror on the windshield. In the exterior wide shots of the station wagon, the rear-view mirror is clearly seen, especially from the back window as they enter the estate and from the front as they park at their bungalow.
When David is talking to his double, there is a bar between them from one point of view, but not the other.
The opening credit sequence is supposed to show the rocket approaching the planet Mars. However, the first shot of the planet isn't Mars but Jupiter, and the second shot, supposedly a close-up of Mars, is in fact a photograph of the Moon.
When the rover is starting out, there's fog drifting across the Martian landscape. Later, when it malfunctions, smoke rises up as flames shoot out underneath. More smoke is seen wafting up from the pile of debris after the rover is destroyed. All of this would indicate an atmosphere containing at least some oxygen, yet Mars lost its atmosphere billions of years ago. Apparently the rover doesn't take samples of the atmosphere as only soil samples are mentioned in the letter being dictated.
372 yards traveled in 6 minutes is not "just under 29 mph". 372 yards in 6 minutes is 2.11 miles per hour; it is a slow walking speed which appears to be the speed that the Mars explorer was moving. (372 yards traveled in 6 minutes = 62 yards per minute = 186 feet per minute = 3.1 feet per second = 2.11 miles per hour)
According to the letter the doctor is dictating, his figures (372 yards traveled in 6 minutes) indicate the rover was moving across the surface of Mars at just under 29 MPH. It clearly wasn't moving that quickly, nor would a sample-taking and analyzing device be moving at that speed.
Seconds before Claire fumbles frantically to open a door, the shadow of a crew member passes her moving in the opposite direction.
About Midway through the movie, David and Webb are standing in the driveway after David's family drives away. David tells Webb he's going to go down to the big house and look around in the bushes behind Webb. To his left, one or more persons can be seen moving around - presumably members of the movie crew.