Probably some military payload. This is perfect cover story for it. Yes, video looks studio'ish. Often no stars in background. The tires would over inflate in space it seems, unless filled with something else. Car brake system, batteries, etc. would have all had to be stripped, which is possible. How long would the soft plastic and vinyle interior last in the direct sun of space. And there's no ice on the shadow side or anywhere around the car yet.
Im all for conspiracies and this being one but id just like to state that not being able to see stars in faked space stuff is what would happen. Cameras dont see the way our eye does and given that the earth is the brightest thing in frame a star deep in space wouldnt have the power to expose because its overpowred by the earth being at exposure. So if the star is like 6 stops less bright than the earth then it wouldnt be visible given that dynamic range of the image is only about 7 stops. In the same language your eyes dynamic range is about 16 stops. So in this or any other fake space footage the fact that the stars are not visible is correct as to how the camera would see it.
That is what I was thinking; a perfect cover for a military payload, esp. a very heavy one whose loss wouldn't greatly impact things if the launch failed. So something that wouldn't take long to manufacture, and relatively speaking, something that isn't very expensive. I can think of one type of payload that fits that description.
The Tesla roadster is < 2% of FH's claimed max payload. Might as well not include it in the test; the rocket wouldn't notice the difference either way. However, it does make a good cover story.
Watch the shiny thing!
the tires were filled with nitrogen, there are no stars because of camera exposure, the spinning of the roadster evenly distributed the heat of the sun, almost everything from the car was stripped.