It's a shot that's in between a profile and a 3/4. For a typical passenger car: Set up your 3/4 driver's side shot, and then pretend you can see through the car. Figure out where the passenger side outside mirror is. That mirror will be somewhere behind the grille, or at the edge of the grille, assuming you could see through the car. To set up the 7/8, move toward the driver's side door, and the mirror's apparent position will move toward the fender. Stop when it's between the grille and the fender corner. Its exact position is of course not possible to predetermine on every car, but I hope that gives you the idea.
You may notice that despite the name 7/8, it's not exactly between the profile and the 3/4. It's closer to the 3/4.