maybe the colors of the explosion look a bit to vivid compared to the footage it is placed in, if you know what I mean.
The matte on the warthog has holes.
Maybe throw some camera shake in there? To sell the effect of how much damage the A10 is doing? Maybe make the camera shake a bit from the plane flying so close to the ground as well? It's up to you, thought it looked pretty good.
You might want to use a little grading, so the Warthog matches the scene better.