I've tried this both ways, as a passenger and as the driver. For example, this other video was shot riding the passenger seat as you described. Aside from using course lock to fly backwards, here are other lessons I've learned: (1) It is best to practice driving your route without the craft to decide speed, direction, and camera angles; (2) If you have a driver, one should come up with clear commands for speed adjustments and aborting the run; (3) if your vehicle has a roof, you should anticipate either losing line of sight or keeping the craft low in the horizon; (3) if you are driving off-road or on uneven road surfaces, it is going to be difficult to impossible to avoid small undesired inputs to the controls that are going to spoil your shots with unintended course corrections or uneven speed.
Of course these videos aren't great examples of me putting these lessons to use, but rather the shots I captured while learning these lessons. For example, this video features me frantically trying to give cues to my driver on speed corrections, while losing line of sight, and nearly crashing a dozen times. Worse yet, if you mess all of these things up and/or blow the exposure settings like I did here, reshoots are not an option unless you've brought a truckload of batteries.
In the end, the selflies are a bit easier for the close up forward shots as they take one complication out of the equation: the communication between the driver and pilot. It is easier to control variations in speed between the vehicle and craft when one has control of both simultaneously, albeit this probably isn't for everyone.