There look to be some good angles there. The first one is nice and low, which helps to make the car a bit more 'imposing'.
As Fruitcake said though, the sense of speed is missing.
If you're looking to improve these then lowering the shutter speed would be a good place to start, 1/1250 is a bit excessive... 1/320 should be fine for a head on shot, somewhat less for pans (try 1/200 or so).
Paul