Very much this! Put your head right at the top of the slot and you will clear every time!
Just don't try it with landing gear down, the Corvette with LG down is just inches clearance in the slot, that lesson costed me 3 rebuys right after I first got it, that was painful.
I've tried it all. If I put my head right at the top of the slot, I hit the top of the slot. If I aim lower down I either hit the bottom or the side, sometimes both. I've given up trying to get it right as it's too stressful. I alway put on shields and let them take the strain.