1. poor choice of DOF or poor composition depending on your opinion if its purely portrait u going for a better crop would have worked, if not u could have done with been at least f8 to bring those jets into focus.
2. as awesome shots said wrong time of day but this isn't always avoidable u could have used a large translucent reflector/diffuser to soften the light and a kick of fill flash or off camera flash to balance the difference between the hot sun and dark shade.
3. could have done with a flash, but also your couple seams slightly awkward bring them slightly closer together, also the white balance is completely off, if possible shoot in raw at, I would also as much as possible avoid AWB.
4. reasonably well composed but the window screen is filthy and the rock chips are distracting (obv you can heal tool the rock chips) also if auto photography is your bag wheel and trim black/polish can make one hell of a difference to a shot.
5. works for me.
6. as 4 but the background is now distracting, you could burn this out possibly.
hope that's helpful